Terminal device, base station device, communication method, and storage medium

ABSTRACT

A terminal device that communicates with a base station device, the terminal device including: a reception unit that receives a data channel including one or more pieces of data; and a transmission unit that transmits response information to the data on the basis of a parameter regarding reliability of the data.

TECHNICAL FIELD

The present disclosure relates to a terminal device, a base stationdevice, a communication method, and a storage medium.

BACKGROUND ART

A radio access system and a radio network for cellular mobilecommunication (hereinafter, also referred to as “Long Term Evolution(LTE)”, “LTE-Advanced (LTE-A)”, “LTE-Advanced Pro (LTE-A Pro)”, “NewRadio (NR)”, “New Radio Access Technology (NRAT)”, “Evolved UniversalTerrestrial Radio Access (EUTRA)”, or “Further EUTRA (FEUTRA)”) havebeen studied in the Third Generation Partnership Project (3GPP). Notethat, in the following description, LTE includes LTE-A, LTE-A Pro, andEUTRA, and NR includes NRAT and FEUTRA. In LTE and NR, a base stationdevice (base station) is also referred to as an evolved NodeB (eNodeB)in LTE and as gNodeB in NR, and a terminal device (mobile station,mobile station device, terminal) is also referred to as User Equipment(UE). LTE and NR are cellular communication systems in which a pluralityof areas covered by a base station device are arranged in a cell form. Asingle base station device may manage a plurality of cells.

NR is a radio access technology (RAT) different from LTE, as anext-generation radio access system for LTE. NR is an access technologythat can cope with various use cases including enhanced mobile broadband(eMBB), massive machine type communications (mMTC), and ultra reliableand low latency communications (URLLC). NR is studied aiming at atechnical framework coping with usage scenarios, requirements, andarrangement scenarios in those use cases. Details of scenarios andrequirements in NR are disclosed in Non-Patent Document 1.

In particular, URLLC requires both high reliability and short delay.Repeating retransmission over time improves reliability but increasesdelay time. However, the delay time also includes the time taken toretransmit data in a case where the data is not correctly received.Therefore, reduction of the retransmission time is important forimplementing low delay. Furthermore, for data retransmission,notification is essential of response information indicating whether thedata is correctly received. Details of a notification method of theresponse information in LTE so far are disclosed in Non-Patent Document2.

CITATION LIST Non-Patent Document

Non-patent document 1: 3rd Generation Partnership Project; TechnicalSpecification Group Radio Access Network; Study on Scenarios andRequirements for Next Generation Access Technologies; (Release 14), 3GPPTR 38.913 V14.1.0 (2016-12). Non-patent document 2: 3rd GenerationPartnership Project; Technical Specification Group Radio Access Network;Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layerprocedures (Release 14), 3GPP TS 36.213 V14.1.0 (2016-12)

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, even if data can be correctly received, in a case wherenotification of the response information cannot be correctly received,it is necessary to retransmit the data, so that the delay time isgreatly affected. Therefore, to implement URLLC, a technology isrequired for implementing both reliability improvement and low delay fornotification of the response information.

The present disclosure has been made in view of the above problem, andit is an object to provide a base station device, a terminal device, acommunication system, a communication method, and a storage mediumenabled to greatly improve transmission efficiency of the entire systemby improving reliability while ensuring low delay with respect tonotification of the response information in the communication system inwhich the base station device and the terminal device communicate witheach other.

Solutions to Problems

According to the present disclosure, there is provided a terminal devicethat communicates with a base station device, the terminal deviceincluding: a reception unit that receives a data channel including oneor more pieces of data; and a transmission unit that transmits responseinformation to the data on the basis of a parameter regardingreliability of the data.

Furthermore, according to the present disclosure, there is provided abase station device that communicates with a terminal device, the basestation device including: a transmission unit that transmits a datachannel including one or more pieces of data; and a reception unit thatreceives response information to the data on the basis of a parameterregarding reliability of the data.

Furthermore, according to the present disclosure, there is provided acommunication method used by a terminal device that communicates with abase station device, the communication method including: receiving adata channel including one or more pieces of data; and transmittingresponse information to the data on the basis of a parameter regardingreliability of the data.

Furthermore, according to the present disclosure, there is provided acommunication method used by a base station device that communicateswith a terminal device, the communication method including: transmittinga data channel including one or more pieces of data; and receivingresponse information to the data on the basis of a parameter regardingreliability of the data.

Furthermore, according to the present disclosure, there is provided arecording medium that records a program for causing a computer tofunction as: a reception unit that receives a data channel including oneor more pieces of data; and a transmission unit that transmits responseinformation to the data on the basis of a parameter regardingreliability of the data.

Furthermore, according to the present disclosure, there is provided arecording medium that records a program for causing a computer tofunction as: a transmission unit that transmits a data channel includingone or more pieces of data; and a reception unit that receives responseinformation to the data on the basis of a parameter regardingreliability of the data.

Effects of the Invention

As described above, according to the present disclosure, transmissionefficiency can be greatly improved of the entire system by improvingreliability while ensuring low delay with respect to notification of theresponse information in the communication system in which the basestation device and the terminal device communicate with each other.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an example of a setting of a componentcarrier in the present embodiment.

FIG. 2 is a diagram illustrating an example of the setting of thecomponent carrier in the present embodiment.

FIG. 3 is a diagram illustrating an example of a downlink subframe ofLTE in the present embodiment.

FIG. 4 is a diagram illustrating an example of an uplink subframe of LTEin the present embodiment.

FIG. 5 is a diagram illustrating an example of a parameter set regardinga transmission signal in an NR cell.

FIG. 6 is a diagram illustrating an example of a downlink subframe of NRin the present embodiment.

FIG. 7 is a diagram illustrating an example of an uplink subframe of NRin the present embodiment.

FIG. 8 is a schematic block diagram illustrating a configuration of abase station device 1 of the present embodiment.

FIG. 9 is a schematic block diagram illustrating a configuration of aterminal device 2 of the present embodiment.

FIG. 10 illustrates an example of a frame configuration of NR in thepresent embodiment.

FIG. 11 illustrates an example of reliability control of responseinformation to data.

FIG. 12 illustrates an example of a method of multiplexing the responseinformation repeatedly transmitted.

FIG. 13 is a diagram illustrating an example of reliability controlregarding the number of times of repeated transmission.

FIG. 14 is a block diagram illustrating a first example of a schematicconfiguration of an eNB to which a technology according to the presentdisclosure can be applied.

FIG. 15 is a block diagram illustrating a second example of theschematic configuration of the eNB to which the technology according tothe present disclosure can be applied.

FIG. 16 is a block diagram illustrating an example of a schematicconfiguration of a smartphone to which the technology according to thepresent disclosure can be applied.

FIG. 17 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device to which the technologyaccording to the present disclosure can be applied.

MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present disclosure will be described indetail below with reference to the accompanying drawings. Note that, inthe present description and the drawings, constituents havingsubstantially the same functional configuration are denoted by the samereference signs, and redundant explanations will be omitted.Furthermore, unless otherwise stated, technologies, functions, methods,configurations, procedures, and all other descriptions described belowcan be applied to LTE and NR.

<Wireless Communication System in the Present Embodiment>

In the present embodiment, a wireless communication system includes atleast a base station device 1 and a terminal device 2. The base stationdevice 1 can accommodate a plurality of terminal devices. The basestation device 1 can be connected to another base station device bymeans of an X2 interface. Furthermore, the base station device 1 can beconnected to an Evolved Packet Core (EPC) by means of an Si interface.Moreover, the base station device 1 can be connected to a MobilityManagement Entity (MME) by means of an S1-MME interface, and can beconnected to a Serving Gateway (S-GW) by means of an S1-U interface. TheS1 interface supports many-to-many connection between the MME and/orS-GW and the base station device 1. Furthermore, in the presentembodiment, the base station device 1 and the terminal device 2 eachsupport LTE and/or NR.

<Radio Access Technology in the Present Embodiment>

In the present embodiment, the base station device 1 and the terminaldevice 2 each support one or more radio access technologies (RATs). Forexample, the RAT includes LTE and NR. One RAT corresponds to one cell(component carrier). In other words, in a case where a plurality of RATsis supported, those RATs respectively correspond to different cells. Inthe present embodiment, a cell is a combination of a downlink resource,an uplink resource, and/or a sidelink. Furthermore, in the followingdescription, a cell corresponding to LTE is referred to as an LTE cell,and a cell corresponding to NR is referred to as an NR cell.

Downlink communication is communication from the base station device 1to the terminal device 2. Downlink transmission is transmission from thebase station device 1 to the terminal device 2, and is transmission of adownlink physical channel and/or a downlink physical signal. Uplinkcommunication is communication from the terminal device 2 to the basestation device 1. Uplink transmission is transmission from the terminaldevice 2 to the base station device 1, and is transmission of an uplinkphysical channel and/or an uplink physical signal. Sidelinkcommunication is communication from the terminal device 2 to anotherterminal device 2. Sidelink transmission is transmission from theterminal device 2 to another terminal device 2 and is transmission of asidelink physical channel and/or a sidelink physical signal.

The sidelink communication is defined for proximity direct detection andproximity direct communication between terminal devices. The sidelinkcommunication can use a frame configuration similar to that of theuplink and downlink. Furthermore, the sidelink communication can belimited to part (subset) of the uplink resource and/or the downlinkresource.

The base station device 1 and the terminal device 2 can supportcommunication using a set of one or more cells in the downlink, uplinkand/or sidelink. A set of a plurality of cells is also referred to ascarrier aggregation or dual connectivity. Details of the carrieraggregation and dual connectivity will be described later. Furthermore,each cell uses a predetermined frequency bandwidth. The maximum value,the minimum value, and a settable value in the predetermined frequencybandwidth can be defined in advance.

FIG. 1 is a diagram illustrating an example of a setting of thecomponent carrier in the present embodiment. In the example of FIG. 1,one LTE cell and two NR cells are set. The one LTE cell is set as aprimary cell. The two NR cells are set as a primary secondary cell and asecondary cell, respectively. The two NR cells are integrated togetherby carrier aggregation. Furthermore, the LTE cell and the NR cells areintegrated together by dual connectivity. Note that, the LTE cell andthe NR cells may be integrated together by carrier aggregation. In theexample of FIG. 1, since NR can be assisted in connection by the LTEcell that is a primary cell, it does not have to support some functionslike a function for communicating in a stand-alone manner. The functionfor communicating in a stand-alone manner includes a function requiredfor initial connection.

FIG. 2 is a diagram illustrating an example of the setting of thecomponent carrier in the present embodiment. In the example of FIG. 2,two NR cells are set. The two NR cells are set as a primary cell and asecondary cell, respectively, and are integrated together by carrieraggregation. In this case, the NR cells support the function forcommunicating in a stand-alone manner, whereby the assist by the LTEcell is not necessary. Note that, the two NR cells may be integratedtogether by dual connectivity.

<Radio Frame Configuration in the Present Embodiment>

In the present embodiment, a radio frame configured in 10 ms(milliseconds) is defined. Each radio frame includes two half frames.The half frame time interval is 5 ms. Each half frame includes fivesubframes. The subframe time interval is 1 ms and is defined by twoconsecutive slots. The slot time interval is 0.5 ms. The i-th subframein the radio frame includes a (2×i)-th slot and a (2×i+1)-th slot. Thatis, ten subframes are defined in each radio frame.

The subframe includes a downlink subframe, an uplink subframe, a specialsubframe, a sidelink subframe, and the like.

The downlink subframe is a subframe reserved for downlink transmission.The uplink subframe is a subframe reserved for uplink transmission. Thespecial subframe includes three fields. The three fields include aDownlink Pilot Time Slot (DwPTS), a Guard Period (GP), and an UplinkPilot Time Slot (UpPTS). The total length of the DwPTS, GP, and UpPTS is1 ms. The DwPTS is a field reserved for downlink transmission. The UpPTSis a field reserved for uplink transmission. The GP is a field in whichdownlink transmission and uplink transmission are not performed. Notethat, the special subframe may include only the DwPTS and GP, or mayinclude only the GP and UpPTS. The special subframe is arranged betweenthe downlink subframe and the uplink subframe in TDD, and is used toswitch from the downlink subframe to the uplink subframe. The sidelinksubframe is a subframe reserved or set for sidelink communication. Thesidelink is used for proximity direct communication and proximity directdetection between terminal devices.

A single radio frame includes the downlink subframe, the uplinksubframe, the special subframe and/or the sidelink subframe.Furthermore, the single radio frame may include only the downlinksubframe, the uplink subframe, the special subframe, or the sidelinksubframe.

A plurality of radio frame configurations is supported. Each of theradio frame configurations is defined by a frame configuration type.Frame configuration type 1 is applicable only to FDD. Frameconfiguration type 2 is applicable only to TDD. Frame configuration type3 is applicable only to operation of a Licensed Assisted Access (LAA)secondary cell.

In the frame configuration type 2, a plurality of uplink-downlinkconfigurations is defined. In the uplink-downlink configuration, each often subframes in one radio frame corresponds to any of the downlinksubframe, the uplink subframe, and the special subframe. A subframe 0, asubframe 5, and the DwPTS are always reserved for downlink transmission.The UpPTS and a subframe immediately after the UpPTS's special subframeare always reserved for uplink transmission.

In the frame configuration type 3, ten subframes in one radio frame arereserved for downlink transmission. The terminal device 2 can treat asubframe on which a PDSCH or detection signal is not transmitted, as anempty subframe. Unless a predetermined signal, channel and/or downlinktransmission is detected in a subframe, the terminal device 2 assumesthat no signal and/or channel exists in the subframe. Downlinktransmission is occupied by one or a plurality of consecutive subframes.The first subframe of the downlink transmission may be started fromanywhere within the subframe. The last subframe of the downlinktransmission may either be completely occupied or be occupied at a timeinterval defined by the DwPTS.

Note that, in the frame configuration type 3, ten subframes in one radioframe may be reserved for uplink transmission. Furthermore, each of tensubframes in one radio frame may correspond to any of the downlinksubframe, the uplink subframe, the special subframe, and the sidelinksubframe.

The base station device 1 may transmit the downlink physical channel andthe downlink physical signal in the DwPTS of the special subframe. Thebase station device 1 can limit transmission of a PBCH in the DwPTS ofthe special subframe. The terminal device 2 may transmit the uplinkphysical channel and the uplink physical signal in the UpPTS of thespecial subframe. The terminal device 2 can limit transmission of someuplink physical channels and uplink physical signals in the UpPTS of thespecial subframe.

Note that, a time interval in one transmission is referred to as aTransmission Time Interval (TTI), and in LTE, 1 ms (one subframe) isdefined as 1 TTI.

<Frame Configuration of LTE in the Present Embodiment>

FIG. 3 is a diagram illustrating an example of a downlink subframe ofLTE in the present embodiment. The diagram illustrated in FIG. 3 is alsoreferred to as a downlink resource grid of LTE. The base station device1 can transmit a downlink physical channel of LTE and/or a downlinkphysical signal of LTE in the downlink subframe to the terminal device2. The terminal device 2 can receive a downlink physical channel of LTEand/or a downlink physical signal of LTE in the downlink subframe fromthe base station device 1.

FIG. 4 is a diagram illustrating an example of an uplink subframe of LTEin the present embodiment. The diagram illustrated in FIG. 4 is alsoreferred to as an uplink resource grid of LTE. The terminal device 2 cantransmit an uplink physical channel of LTE and/or an uplink physicalsignal of LTE in the uplink subframe to the base station device 1. Thebase station device 1 can receive an uplink physical channel of LTEand/or an uplink physical signal of LTE in the uplink subframe from theterminal device 2.

In the present embodiment, a physical resource of LTE can be defined asfollows. One slot is defined by a plurality of symbols. The physicalsignal or physical channel transmitted in each slot is represented by aresource grid. In the downlink, the resource grid is defined by aplurality of subcarriers in the frequency direction and a plurality ofOFDM symbols in the time direction. In the uplink, the resource grid isdefined by a plurality of subcarriers in the frequency direction and aplurality of SC-FDMA symbols in the time direction. The number ofsubcarriers or resource blocks may be determined depending on thebandwidth of the cell. The number of symbols in one slot is determinedby a type of a Cyclic Prefix (CP). The type of the CP is a normal CP oran extended CP. In the normal CP, the number of OFDM symbols or SC-FDMAsymbols constituting one slot is seven. In the extended CP, the numberof OFDM symbols or SC-FDMA symbols constituting one slot is six. Each ofelements in the resource grid is referred to as a resource element. Theresource element is identified by using a subcarrier index (number) anda symbol index (number). Note that, in the description of the presentembodiment, the OFDM symbol or SC-FDMA symbol is also simply referred toas a symbol.

The resource block is used to map a certain physical channel (such asthe PDSCH or PUSCH) onto a resource element. The resource block includesa virtual resource block and a physical resource block. A certainphysical channel is mapped onto a virtual resource block. The virtualresource block is mapped onto a physical resource block. One physicalresource block is defined by a predetermined number of consecutivesymbols in the time domain. One physical resource block is defined by apredetermined number of consecutive subcarriers in the frequency domain.The number of symbols and the number of subcarriers in one physicalresource block are determined on the basis of the type of the CP in thecell, subcarrier interval, and/or a parameter set by an upper layer, andthe like. For example, in a case where the type of the CP is the normalCP and the subcarrier interval is 15 kHz, the number of symbols in onephysical resource block is 7 and the number of subcarriers is 12. Inthat case, one physical resource block includes (7×12) resourceelements. Physical resource blocks are numbered from zero in thefrequency domain. Furthermore, two resource blocks in one subframecorresponding to the same physical resource block number are defined asa physical resource block pair (PRB pair, RB pair).

In each LTE cell, one predetermined parameter is used in a certainsubframe. For example, the predetermined parameter is a parameter(physical parameter) regarding a transmission signal. The parameterregarding the transmission signal includes the CP length, subcarrierinterval, number of symbols in one subframe (predetermined time length),number of subcarriers in one resource block (predetermined frequencyband), multiple access method, signal waveform, and the like.

In other words, in the LTE cell, a downlink signal and an uplink signaleach are generated by using one predetermined parameter in apredetermined time length (for example, subframe). In other words, theterminal device 2 assumes that the downlink signal transmitted from thebase station device 1 and the uplink signal transmitted to the basestation device 1 each are generated with one predetermined parameter inthe predetermined time length. Furthermore, the base station device 1performs setting so that the downlink signal transmitted to the terminaldevice 2 and the uplink signal transmitted from the terminal device 2each are generated with one predetermined parameter in the predeterminedtime length.

<Frame Configuration of NR in the Present Embodiment>

In each NR cell, one or more predetermined parameters are used in apredetermined time length (for example, subframe, slot, mini-slot,symbol, radio frame). In other words, in the NR cell, a downlink signaland an uplink signal each are generated by using one or morepredetermined parameters in the predetermined time length. In otherwords, the terminal device 2 assumes that the downlink signaltransmitted from the base station device 1 and the uplink signaltransmitted to the base station device 1 each are generated with one ormore predetermined parameters in the predetermined time length.Furthermore, the base station device 1 can perform setting so that thedownlink signal transmitted to the terminal device 2 and the uplinksignal transmitted from the terminal device 2 each are generated withone or more predetermined parameters in the predetermined time length.In a case where a plurality of predetermined parameters is used, signalsgenerated by using those predetermined parameters are multiplexed by apredetermined method. For example, the predetermined method includesFrequency Division Multiplexing (FDM), Time Division Multiplexing (TDM),Code Division Multiplexing (CDM), and/or Spatial Division Multiplexing(SDM), and the like.

For a combination of the predetermined parameters set in the NR cell, aplurality of types can be defined in advance as a parameter set.

FIG. 5 is a diagram illustrating an example of the parameter setregarding a transmission signal in the NR cell. In the example of FIG.5, parameters regarding the transmission signal included in theparameter set are the subcarrier interval, the number of subcarriers perresource block in the NR cell, the number of symbols per subframe, andthe CP length type. The CP length type is a type of the CP length usedin the NR cell. For example, CP length type 1 corresponds to the normalCP in LTE, and CP length type 2 corresponds to the extended CP in LTE.

The parameter set regarding the transmission signal in the NR cell canbe defined individually for the downlink and uplink. Furthermore, theparameter set regarding the transmission signal in the NR cell can beset independently for the downlink and uplink.

FIG. 6 is a diagram illustrating an example of a downlink subframe of NRin the present embodiment. In the example of FIG. 6, signals generatedby using a parameter set 1, a parameter set 0, and a parameter set 2 aresubjected to FDM in the cell (system bandwidth). The diagram illustratedin FIG. 6 is also referred to as a downlink resource grid of NR. Thebase station device 1 can transmit a downlink physical channel of NRand/or a downlink physical signal of NR in the downlink subframe to theterminal device 2. The terminal device 2 can receive the downlinkphysical channel of NR and/or the downlink physical signal of NR in thedownlink subframe from the base station device 1.

FIG. 7 is a diagram illustrating an example of an uplink subframe of NRin the present embodiment. In the example of FIG. 7, signals generatedby using the parameter set 1, the parameter set 0, and the parameter set2 are subjected to FDM in the cell (system bandwidth). The diagramillustrated in FIG. 6 is also referred to as an uplink resource grid ofNR. The base station device 1 can transmit an uplink physical channel ofNR and/or an uplink physical signal of NR in the uplink subframe to theterminal device 2. The terminal device 2 can receive an uplink physicalchannel of NR and/or an uplink physical signal of NR in the uplinksubframe from the base station device 1.

Furthermore, in NR, the subframe, slot, and mini-slot are defined asunits in the time direction.

The subframe has a time interval of 1 ms and includes 14 symbols at apredetermined subcarrier interval (for example, 15 kHz). Note that, thesubframe may be defined by a predetermined number of symbols, and thesubframe length in that case is variable depending on the subcarrierinterval.

The slot can be defined as a processing unit in the time direction towhich data or the like is allocated. The slot includes a predeterminednumber of symbols, and is set uniquely for the base station, cell and/orterminal. For example, the slot includes 7 or 14 symbols.

Similarly to the slot, the mini-slot can be defined as a processing unitin the time direction to which data or the like is allocated. However,the mini-slot includes fewer symbols than the number of symbolsconstituting the slot. Furthermore, a possible value of the number ofsymbols constituting the mini-slot may be changed depending on thecarrier frequency. In the case of a predetermined carrier frequency (forexample, 6 GHz) or higher, the minimum value of the number of symbolsconstituting the mini-slot is one, and in the case of less than thepredetermined carrier frequency (for example 6 GHz), the minimum valueof the number of symbols constituting the mini-slot is two. Note that,the mini-slot may be used as part of the slot.

<Antenna Port in the Present Embodiment>

An antenna port is defined to allow a propagation channel carrying acertain symbol to be inferred from a propagation channel carryinganother symbol at the same antenna port. For example, it can be assumedthat different physical resources in the same antenna port aretransmitted on the same propagation channel. In other words, a symbol ata certain antenna port can be demodulated by estimating a propagationchannel with a reference signal at the antenna port. Furthermore, thereis one resource grid for each antenna port. The antenna port is definedby the reference signal. Furthermore, each reference signal can define aplurality of antenna ports.

The antenna port is specified or identified by an antenna port number.For example, antenna ports 0 to 3 are antenna ports on which CRSs aretransmitted. In other words, PDSCHs transmitted on the antenna ports 0to 3 can be demodulated by CRSs corresponding to the antenna ports 0 to3.

Two antenna ports can be expressed as quasi co-location (QCL) in a casewhere a predetermined condition is satisfied. The predeterminedcondition is that global characteristics of a propagation channelcarrying a symbol at a certain antenna port can be inferred from apropagation channel carrying a symbol at another antenna port. Theglobal characteristics include delay dispersion, Doppler spread, Dopplershift, average gain, and/or average delay.

In the present embodiment, the antenna port number may be defineddifferently for each RAT, or may be commonly defined among RATs. Forexample, the antenna ports 0 to 3 in LTE are antenna ports on which CRSsare transmitted. In NR, the antenna ports 0 to 3 can be antenna ports onwhich CRSs similar to those in LTE are transmitted. Furthermore, in NR,an antenna port on which a CRS similar to that of LTE is transmitted canbe an antenna port number different from the antenna ports 0 to 3. Inthe description of the present embodiment, a predetermined antenna portnumber can be applied to LTE and/or NR.

<Physical Channel and Physical Signal in the Present Embodiment>

In the present embodiment, a physical channel and a physical signal areused.

The physical channel includes a downlink physical channel, an uplinkphysical channel, and a sidelink physical channel. The physical signalincludes a downlink physical signal, an uplink physical signal, and asidelink physical signal.

The physical channel and the physical signal in LTE are also referred toas an LTE physical channel and an LTE physical signal, respectively. Thephysical channel and physical signal in NR are also referred to as an NRphysical channel and an NR physical signal, respectively. The LTEphysical channel and the NR physical channel can be defined as differentphysical channels, respectively. The LTE physical signal and the NRphysical signal can be defined as different physical signals,respectively. In the description of the present embodiment, the LTEphysical channel and the NR physical channel are also simply referred toas a physical channel, and the LTE physical signal and the NR physicalsignal are also simply referred to as a physical signal. In other words,the description for the physical channel is applicable to both the LTEphysical channel and the NR physical channel. The description for thephysical signal is applicable to both the LTE physical signal and the NRphysical signal.

<NR Physical Channel and NR Physical Signal in the Present Embodiment>

The descriptions for the physical channel and physical signal in LTE arealso applicable to the NR physical channel and NR physical signal,respectively. The NR physical channel and the NR physical signal arereferred to as follows.

An NR downlink physical channel includes an NR-PBCH, NR-PCFICH,NR-PHICH, NR-PDCCH, NR-EPDCCH, NR-MPDCCH, NR-R-PDCCH, NR-PDSCH, NR-PMCH,and the like.

An NR downlink physical signal includes an NR-SS, NR-DL-RS, NR-DS, andthe like. The NR-SS includes an NR-PSS, NR-SSS, and the like. The NR-RSincludes NR-CRS, NR-PDSCH-DMRS, NR-EPDCCH-DMRS, NR-PRS, NR-CSI-RS,NR-TRS, and the like.

An NR uplink physical channel includes an NR-PUSCH, NR-PUCCH, NR-PRACH,and the like.

An NR uplink physical signal includes an NR-UL-RS. The NR-UL-RS includesan NR-UL-DMRS, NR-SRS, and the like.

An NR sidelink physical channel includes an NR-PSBCH, NR-PSCCH,NR-PSDCH, NR-PSSCH, and the like.

<Downlink Physical Channel in the Present Embodiment>

The PBCH is used to broadcast a Master Information Block (MIB) that isbroadcast information unique to a serving cell of the base stationdevice 1. The PBCH is transmitted only in the subframe 0 in the radioframe. The MIB can be updated at intervals of 40 ms. The PBCH isrepeatedly transmitted in a 10 ms period. Specifically, initialtransmission of the MIB is performed in the subframe 0 in a radio framethat satisfies a condition that a remainder obtained by dividing aSystem Frame Number (SFN) by four is zero, and retransmission(repetition) of the MIB is performed in the subframe 0 in all otherradio frames. The SFN is a radio frame number (system frame number). TheMIB is system information. For example, the MIB includes informationindicating the SFN.

The PCFICH is used to transmit information regarding the number of OFDMsymbols used for transmission of the PDCCH. A region indicated by thePCFICH is also referred to as a PDCCH region. Information transmitted onthe PCFICH is also referred to as a Control Format Indicator (CFI).

The PHICH is used to transmit HARQ-ACK (HARQ indicator, HARQ feedback,response information) indicating acknowledgement (ACK) or negativeacknowledgement (NACK) for uplink data (Uplink Shared Channel: UL-SCH)received by the base station device 1. For example, in a case where theterminal device 2 receives HARQ-ACK indicating ACK, the correspondinguplink data is not retransmitted. For example, in a case where theterminal device 2 receives HARQ-ACK indicating NACK, the terminal device2 retransmits the corresponding uplink data in a predetermined uplinksubframe. A certain PHICH transmits HARQ-ACK for certain uplink data.The base station device 1 transmits each piece of HARQ-ACK for aplurality of pieces of uplink data included in the same PUSCH by using aplurality of PHICHs.

The PDCCH and the EPDCCH are used to transmit Downlink ControlInformation (DCI). Mapping of an information bit of the downlink controlinformation is defined as a DCI format. The downlink control informationincludes a downlink grant and an uplink grant. The downlink grant isalso referred to as downlink assignment or downlink allocation.

The PDCCH is transmitted by a set of one or a plurality of consecutiveControl Channel Elements (CCEs). The CCE includes nine Resource ElementGroups (REGs). The REG includes four resource elements. In a case wherea PDCCH includes n consecutive CCEs, the PDCCH starts from a CCE thatsatisfies a condition that a remainder obtained by dividing i that is anindex (number) of the CCE is zero.

The EPDCCH is transmitted by a set of one or a plurality of consecutiveenhanced control channel elements (ECCEs). The ECCE includes a pluralityof Enhanced Resource Element Groups (EREGs).

The downlink grant is used for scheduling of the PDSCH in a certaincell. The downlink grant is used for scheduling of the PDSCH in the samesubframe as a subframe on which the downlink grant is transmitted. Theuplink grant is used for scheduling of the PUSCH in a certain cell. Theuplink grant is used for scheduling of a single PUSCH in a subframeafter four or more subframes from a subframe on which the uplink grantis transmitted.

In the DCI, a cyclic redundancy check (CRC) parity bit is added. The CRCparity bit is scrambled with a Radio Network Temporary Identifier(RNTI). The RNTI is an identifier that can be defined or set dependingon a purpose of the DCI, and the like. The RNTI is an identifier definedin advance in a specification, an identifier set as information uniqueto a cell, an identifier set as information unique to the terminaldevice 2, or an identifier set as information unique to a groupbelonging to the terminal device 2. For example, in monitoring of thePDCCH or EPDCCH, the terminal device 2 descrambles the CRC parity bitadded to the DCI with a predetermined RNTI, to identify whether the CRCis correct. In a case where the CRC is correct, it is known that the DCIis for the terminal device 2.

The PDSCH is used to transmit downlink data (Downlink Shared Channel:DL-SCH). Furthermore, the PDSCH is also used to transmit controlinformation of the upper layer.

The PMCH is used to transmit multicast data (Multicast Channel: MCH).

In the PDCCH region, a plurality of PDCCHs may be frequency, time,and/or spatially multiplexed. In an EPDCCH region, a plurality ofEPDCCHs may be frequency, time, and/or spatially multiplexed. In a PDSCHregion, a plurality of PDSCHs may be frequency, time, and/or spatiallymultiplexed. The PDCCH, PDSCH and/or EPDCCH may be frequency, time,and/or spatially multiplexed.

<Downlink Physical Signal in the Present Embodiment>

A synchronization signal is used by the terminal device 2 forsynchronization in the downlink frequency domain and/or time domain. Thesynchronization signal includes a Primary Synchronization Signal (PSS)and a Secondary Synchronization Signal (SSS). The synchronization signalis arranged in a predetermined subframe in the radio frame. For example,in a TDD system, the synchronization signal is arranged in subframes 0,1, 5, and 6 in the radio frame. In an FDD system, the synchronizationsignal is arranged in subframes 0 and 5 in the radio frame.

The PSS may be used for coarse frame/symbol timing synchronization(synchronization in time domain) and for identification of a cellidentification group. The SSS may be used for more accurate frame timingsynchronization, cell identification, and CP length detection. That is,frame timing synchronization and cell identification can be performed byuse of the PSS and SSS.

A downlink reference signal is used by the terminal device 2 to performpropagation path estimation of the downlink physical channel,propagation path correction, calculation of downlink Channel StateInformation (CSI), and/or measurement of positioning of the terminaldevice 2.

The CRS is transmitted on the entire band of the subframe. The CRS isused to receive (demodulate) the PBCH, PDCCH, PHICH, PCFICH, and PDSCH.The CRS may be used by the terminal device 2 to calculate the downlinkchannel state information. The PBCH, PDCCH, PHICH, and PCFICH aretransmitted on an antenna port used for transmission of the CRS. The CRSsupports a configuration of one, two, or four antenna ports. The CRS istransmitted on one or a plurality of the antenna ports 0 to 3.

A URS associated with the PDSCH is transmitted on the subframe and bandused for transmission of the PDSCH with which the URS is associated. TheURS is used to demodulate the PDSCH with which the URS is associated.The URS associated with the PDSCH is transmitted on one or a pluralityof antenna ports 5, and 7 to 14.

The PDSCH is transmitted on an antenna port used for transmission of theCRS or URS on the basis of a transmission mode and a DCI format. The DCIformat 1A is used for scheduling of the PDSCH transmitted on the antennaport used for transmission of the CRS. The DCI format 2D is used forscheduling of the PDSCH transmitted on an antenna port used fortransmission of the URS.

The DMRS associated with the EPDCCH is transmitted on the subframe andband used for transmission of the EPDCCH with which the DMRS isassociated. The DMRS is used to demodulate the EPDCCH with which theDMRS is associated. The EPDCCH is transmitted on an antenna port usedfor transmission of the DMRS. The DMRS associated with the EPDCCH istransmitted on one or a plurality of antenna ports 107 to 114.

The CSI-RS is transmitted on a set subframe. The resource on which theCSI-RS is transmitted is set by the base station device 1. The CSI-RS isused by the terminal device 2 to calculate downlink channel stateinformation. The terminal device 2 performs signal measurement (channelmeasurement) by using the CSI-RS. The CSI-RS supports setting of some orall of 1, 2, 4, 8, 12, 16, 24, and 32 antenna ports. The CSI-RS istransmitted on one or a plurality of antenna ports 15 to 46. Note that,an antenna port to be supported may be determined on the basis ofterminal device capability of the terminal device 2, a setting of an RRCparameter, and/or a transmission mode to be set, and the like.

A ZP CSI-RS resource is set by the upper layer. The ZP CSI-RS resourcemay be transmitted with zero output power. In other words, the ZP CSI-RSresource may transmit nothing. On the resource set by the ZP CSI-RS, thePDSCH and EPDCCH are not transmitted. For example, the ZP CSI-RSresource is used by a neighboring cell to transmit an NZP CSI-RS.Furthermore, for example, the ZP CSI-RS resource is used to measureCSI-IM. Furthermore, for example, the ZP CSI-RS resource is a resourceon which a predetermined channel such as the PDSCH is not transmitted.In other words, the predetermined channel is mapped (rate matched andpunctured) except for the ZP CSI-RS resource.

<Uplink Physical Channel in the Present Embodiment>

The PUCCH is a physical channel used to transmit uplink controlinformation (UCI). The uplink control information includes downlinkchannel state information (CSI), a scheduling request (SR) indicating arequest for a PUSCH resource, and HARQ-ACK for downlink data (transportblock: TB, downlink-shared channel: DL-SCH). The HARQ-ACK is alsoreferred to as ACK/NACK, HARQ feedback, or response information.Furthermore, the HARQ-ACK for downlink data indicates ACK, NACK or DTX.

The PUSCH is a physical channel used to transmit uplink data(Uplink-Shared Channel: UL-SCH). Furthermore, the PUSCH may be used totransmit the HARQ-ACK and/or the channel state information along withthe uplink data. Furthermore, the PUSCH may be used to transmit only thechannel state information or only the HARQ-ACK and channel stateinformation.

The PRACH is a physical channel used to transmit a random accesspreamble. The PRACH can be used for the terminal device 2 to synchronizewith the base station device 1 in the time domain. Furthermore, thePRACH is also used to indicate an initial connection establishmentprocedure (processing), a handover procedure, a connectionre-establishment procedure, synchronization for uplink transmission(timing adjustment), and/or the request for the PUSCH resource.

In a PUCCH region, a plurality of PUCCHs is frequency, time, space,and/or code multiplexed. In the PUSCH region, a plurality of PUSCHs maybe frequency, time, space, and/or code multiplexed. The PUCCH and PUSCHmay be frequency, time, space, and/or code multiplexed. The PRACH may bearranged in a single subframe or over two subframes. A plurality ofPRACHs may be code-multiplexed.

<Configuration Example of Base Station Device 1 in the PresentEmbodiment>

FIG. 8 is a schematic block diagram illustrating a configuration of thebase station device 1 of the present embodiment. As illustrated, thebase station device 1 includes an upper layer processing unit 101, acontrol unit 103, a reception unit 105, a transmission unit 107, and atransmission/reception antenna 109. Furthermore, the reception unit 105includes a decoding unit 1051, a demodulation unit 1053, ademultiplexing unit 1055, a wireless reception unit 1057, and a channelmeasurement unit 1059. Furthermore, the transmission unit 107 includesan encoding unit 1071, a modulation unit 1073, a multiplexing unit 1075,a wireless transmission unit 1077, and a downlink reference signalgeneration unit 1079.

As described above, the base station device 1 can support one or moreRATs. Some or all of the units included in the base station device 1illustrated in FIG. 8 can be individually configured depending on theRAT. For example, the reception unit 105 and the transmission unit 107are individually configured for LTE and NR. Furthermore, in the NR cell,some or all of the units included in the base station device 1illustrated in FIG. 8 can be individually configured depending on theparameter set regarding the transmission signal. For example, in acertain NR cell, the wireless reception unit 1057 and the wirelesstransmission unit 1077 can be individually configured depending on theparameter set regarding the transmission signal.

The upper layer processing unit 101 performs processing of a MediumAccess Control (MAC) layer, a Packet Data Convergence Protocol (PDCP)layer, a Radio Link Control (RLC) layer, and a Radio Resource Control(RRC) layer. Furthermore, the upper layer processing unit 101 generatescontrol information to control the reception unit 105 and thetransmission unit 107, and outputs the control information to thecontrol unit 103.

The control unit 103 controls the reception unit 105 and thetransmission unit 107 on the basis of the control information from theupper layer processing unit 101. The control unit 103 generates controlinformation to the upper layer processing unit 101, and outputs thecontrol information to the upper layer processing unit 101. The controlunit 103 inputs a decoded signal from the decoding unit 1051 and achannel estimation result from the channel measurement unit 1059. Thecontrol unit 103 outputs a signal to be encoded to the encoding unit1071. Furthermore, the control unit 103 is used to control the whole orpart of the base station device 1.

The upper layer processing unit 101 performs processing and managementregarding RAT control, radio resource control, subframe setting,scheduling control, and/or CSI report control. The processing andmanagement in the upper layer processing unit 101 are performed for eachterminal device or commonly for terminal devices connected to the basestation device. The processing and management in the upper layerprocessing unit 101 may be performed only in the upper layer processingunit 101, or may be acquired from an upper node or another base stationdevice. Furthermore, the processing and management in the upper layerprocessing unit 101 may be performed individually depending on the RAT.For example, the upper layer processing unit 101 individually performsprocessing and management in LTE and processing and management in NR.

In the RAT control in the upper layer processing unit 101, managementregarding the RAT is performed. For example, in the RAT control,management regarding LTE and/or management regarding NR are performed.Management regarding NR includes setting and processing of the parameterset regarding the transmission signal in the NR cell.

In the radio resource control in the upper layer processing unit 101,generation and/or management is performed of downlink data (transportblock), system information, an RRC message (RRC parameter), and/or a MACcontrol element (CE).

In the subframe setting in the upper layer processing unit 101,management is performed of subframe setting, subframe pattern setting,uplink-downlink setting, uplink reference UL-DL setting, and/or downlinkreference UL-DL setting. Note that, the subframe setting in the upperlayer processing unit 101 is also referred to as base station subframesetting. Furthermore, the subframe setting in the upper layer processingunit 101 can be determined on the basis of the uplink traffic volume andthe downlink traffic volume. Furthermore, the subframe setting in theupper layer processing unit 101 can be determined on the basis of ascheduling result of the scheduling control in the upper layerprocessing unit 101.

In the scheduling control in the upper layer processing unit 101, on thebasis of received channel state information and a propagation pathestimation value and channel quality input from the channel measurementunit 1059, and the like, a frequency and a subframe to which thephysical channel is allocated, an encoding rate, a modulation system,transmission power, and the like of the physical channel are determined.For example, the control unit 103 generates control information (DCIformat) on the basis of the scheduling result of the scheduling controlin the upper layer processing unit 101.

In the CSI report control in the upper layer processing unit 101, CSIreporting of the terminal device 2 is controlled. For example, settingis controlled regarding a CSI reference resource for making assumptionto calculate CSI in the terminal device 2.

In accordance with the control from the control unit 103, the receptionunit 105 receives a signal transmitted from the terminal device 2 viathe transmission/reception antenna 109, and further performs receptionprocessing such as separation, demodulation, decoding, and the like, andoutputs to the control unit 103 information subjected to the receptionprocessing. Note that, the reception processing in the reception unit105 is performed on the basis of a setting defined in advance or asetting of which the base station device 1 notifies the terminal device2.

The wireless reception unit 1057 performs, on the uplink signal receivedvia the transmission/reception antenna 109, conversion (down convert) toan intermediate frequency, removal of an unnecessary frequencycomponent, control of amplification level to appropriately maintain thesignal level, quadrature demodulation based on in-phase and quadraturecomponents of the received signal, conversion of an analog signal to adigital signal, removal of a Guard Interval (GI), and/or extraction of afrequency domain signal by Fast Fourier Transform (FFT).

The demultiplexing unit 1055 separates an uplink channel such as thePUCCH or PUSCH and/or an uplink reference signal from the signal inputfrom the wireless reception unit 1057. The demultiplexing unit 1055outputs the uplink reference signal to the channel measurement unit1059. The demultiplexing unit 1055 performs propagation pathcompensation for the uplink channel from the propagation path estimationvalue input from the channel measurement unit 1059.

The demodulation unit 1053 performs, on a modulation symbol of theuplink channel, demodulation of the reception signal by using amodulation system such as Binary Phase Shift Keying (BPSK), QuadraturePhase Shift Keying (QPSK), Quadrature Amplitude Modulation (16QAM),64QAM, 256QAM, or the like. The demodulation unit 1053 performsseparation and demodulation of the MIMO multiplexed uplink channel.

The decoding unit 1051 performs decoding processing on an encoded bit ofthe uplink channel demodulated. The decoded uplink data and/or uplinkcontrol information is output to the control unit 103. The decoding unit1051 performs, on the PUSCH, decoding processing for each transportblock.

The channel measurement unit 1059 measures the propagation pathestimation value and/or channel quality and the like from the uplinkreference signal input from the demultiplexing unit 1055, and outputsthe measured values to the demultiplexing unit 1055 and/or the controlunit 103. For example, the channel measurement unit 1059 measures thepropagation path estimation value for performing propagation pathcompensation for the PUCCH or PUSCH by using the UL-DMRS, and measuresthe channel quality in the uplink by using the SRS.

In accordance with the control from the control unit 103, thetransmission unit 107 performs transmission processing such as encoding,modulation, and multiplexing on the downlink control information and thedownlink data input from the upper layer processing unit 101. Forexample, the transmission unit 107 generates and multiplexes the PHICH,PDCCH, EPDCCH, PDSCH, and downlink reference signal, to generate atransmission signal. Note that, the transmission processing intransmission unit 107 is performed on the basis of a setting defined inadvance, a setting of which the base station device 1 notifies theterminal device 2, or a setting received via the PDCCH or EPDCCHtransmitted on the same subframe.

The encoding unit 1071 performs encoding on an HARQ indicator(HARQ-ACK), downlink control information, and downlink data input fromthe control unit 103, by using a predetermined encoding system such asblock encoding, convolutional encoding, turbo encoding, or the like. Themodulation unit 1073 modulates an encoded bit input from the encodingunit 1071 with a predetermined modulation system such as BPSK, QPSK,16QAM, 64QAM, 256QAM, or the like. The downlink reference signalgeneration unit 1079 generates a downlink reference signal on the basisof a physical cell identification (PCI), an RRC parameter set in theterminal device 2, and the like. The multiplexing unit 1075 multiplexesa modulation symbol of each channel and the downlink reference signal,and arranges them in a predetermined resource element.

The wireless transmission unit 1077 performs, on the signal from themultiplexing unit 1075, processing such as conversion to a time domainsignal by Inverse Fast Fourier Transform (IFFT), addition of a guardinterval, generation of a baseband digital signal, conversion to ananalog signal, quadrature modulation, conversion of an intermediatefrequency signal to a high frequency signal (up convert), removal of anextra frequency component, power amplification, or the like, to generatea transmission signal. The transmission signal output from the wirelesstransmission unit 1077 is transmitted from the transmission/receptionantenna 109.

<Configuration Example of Terminal Device 2 in the Present Embodiment>

FIG. 9 is a schematic block diagram illustrating a configuration of theterminal device 2 of the present embodiment. As illustrated, theterminal device 2 includes an upper layer processing unit 201, a controlunit 203, a reception unit 205, a transmission unit 207, and atransmission/reception antenna 209. Furthermore, the reception unit 205includes a decoding unit 2051, a demodulation unit 2053, ademultiplexing unit 2055, a wireless reception unit 2057, and a channelmeasurement unit 2059. Furthermore, the transmission unit 207 includesan encoding unit 2071, a modulation unit 2073, a multiplexing unit 2075,a wireless transmission unit 2077, and an uplink reference signalgeneration unit 2079.

As described above, the terminal device 2 can support one or more RATs.Some or all of the units included in the terminal device 2 illustratedin FIG. 9 can be individually configured depending on the RAT. Forexample, the reception unit 205 and the transmission unit 207 areindividually configured for LTE and NR. Furthermore, in the NR cell,some or all of the units included in the terminal device 2 illustratedin FIG. 9 can be individually configured depending on the parameter setregarding the transmission signal. For example, in a certain NR cell,the wireless reception unit 2057 and the wireless transmission unit 2077can be individually configured depending on the parameter set regardingthe transmission signal.

The upper layer processing unit 201 outputs uplink data (transportblock) to the control unit 203. The upper layer processing unit 201performs processing of a Medium Access Control (MAC) layer, a PacketData Convergence Protocol (PDCP) layer, a Radio Link Control (RLC)layer, and a Radio Resource Control (RRC) layer. Furthermore, the upperlayer processing unit 201 generates control information to control thereception unit 205 and the transmission unit 207, and outputs thecontrol information to the control unit 203.

The control unit 203 controls the reception unit 205 and thetransmission unit 207 on the basis of the control information from theupper layer processing unit 201. The control unit 203 generates controlinformation to the upper layer processing unit 201, and outputs thecontrol information to the upper layer processing unit 201. The controlunit 203 inputs a decoded signal from the decoding unit 2051 and achannel estimation result from the channel measurement unit 2059. Thecontrol unit 203 outputs a signal to be encoded to the encoding unit2071. Furthermore, the control unit 203 may be used to control the wholeor part of the terminal device 2.

The upper layer processing unit 201 performs processing and managementregarding RAT control, radio resource control, subframe setting,scheduling control, and/or CSI report control. The processing andmanagement in the upper layer processing unit 201 are performed on thebasis of a setting defined in advance and/or a setting based on controlinformation set or received from the base station device 1. For example,the control information from the base station device 1 includes an RRCparameter, a MAC control element, or DCI. Furthermore, the processingand management in the upper layer processing unit 201 may be performedindividually depending on the RAT. For example, the upper layerprocessing unit 201 individually performs processing and management inLTE and processing and management in NR.

In the RAT control in the upper layer processing unit 201, managementregarding the RAT is performed. For example, in the RAT control,management regarding LTE and/or management regarding NR are performed.Management regarding NR includes setting and processing of the parameterset regarding the transmission signal in the NR cell.

In the radio resource control in the upper layer processing unit 201,management is performed of setting information in the terminal device 2.In the radio resource control in the upper layer processing unit 201,generation and/or management is performed of uplink data (transportblock), system information, an RRC message (RRC parameter), and/or a MACcontrol element (CE).

In the subframe setting in the upper layer processing unit 201, subframesetting in the base station device 1 and/or a base station devicedifferent from the base station device 1 is managed. The subframesetting includes uplink or downlink setting for the subframe, subframepattern setting, uplink-downlink setting, uplink reference UL-DLsetting, and/or downlink reference UL-DL setting. Note that, thesubframe setting in the upper layer processing unit 201 is also referredto as terminal subframe setting.

In the scheduling control in the upper layer processing unit 201, on thebasis of the DCI (scheduling information) from the base station device1, control information is generated for performing control regardingscheduling for the reception unit 205 and the transmission unit 207.

In the CSI report control in the upper layer processing unit 201,control is performed regarding CSI reporting to the base station device1. For example, in the CSI report control, setting is controlledregarding a CSI reference resource for making assumption to calculateCSI in the channel measurement unit 2059. In the CSI report control, aresource (timing) used to report the CSI is controlled on the basis ofthe DCI and/or the RRC parameter.

In accordance with the control from the control unit 203, the receptionunit 205 receives a signal transmitted from the base station device 1via the transmission/reception antenna 209, and further performsreception processing such as separation, demodulation, decoding, and thelike, and outputs to the control unit 203 information subjected to thereception processing. Note that, the reception processing in thereception unit 205 is performed on the basis of a setting defined inadvance, or a notification or setting from the base station device 1.

The wireless reception unit 2057 performs, on the uplink signal receivedvia the transmission/reception antenna 209, conversion (down convert) toan intermediate frequency, removal of an unnecessary frequencycomponent, control of amplification level to appropriately maintain thesignal level, quadrature demodulation based on in-phase and quadraturecomponents of the received signal, conversion of an analog signal to adigital signal, removal of a Guard Interval (GI), and/or extraction of afrequency domain signal by Fast Fourier Transform (FFT).

The demultiplexing unit 2055 separates a downlink channel such as thePHICH, PDCCH, EPDCCH, or PDSCH, a downlink synchronization signal,and/or a downlink reference signal from the signal input from thewireless reception unit 2057. The demultiplexing unit 2055 outputs thedownlink reference signal to the channel measurement unit 2059. Thedemultiplexing unit 2055 performs propagation path compensation for thedownlink channel from a propagation path estimation value input from thechannel measurement unit 2059.

The demodulation unit 2053 performs, on a modulation symbol of thedownlink channel, demodulation of the reception signal by using amodulation system such as BPSK, QPSK, 16QAM, 64QAM, 256QAM, or the like.The demodulation unit 2053 performs separation and demodulation of theMIMO multiplexed downlink channel.

The decoding unit 2051 performs decoding processing on an encoded bit ofthe downlink channel demodulated. The decoded downlink data and/ordownlink control information is output to the control unit 203. Thedecoding unit 2051 performs, on the PDSCH, decoding processing for eachtransport block.

The channel measurement unit 2059 measures the propagation pathestimation value and/or channel quality and the like from the downlinkreference signal input from the demultiplexing unit 2055, and outputsthe measured values to the demultiplexing unit 2055 and/or the controlunit 203. The downlink reference signal used for measurement by thechannel measurement unit 2059 may be determined on the basis of at leasta transmission mode set by the RRC parameter, and/or another RRCparameter. For example, a DL-DMRS measures the propagation pathestimation value for performing propagation path compensation for thePDSCH or EPDCCH. The CRS measures the propagation path estimation valuefor performing propagation path compensation for the PDCCH or PDSCH,and/or a channel in the downlink for reporting the CSI. The CSI-RSmeasures the channel in the downlink for reporting the CSI. The channelmeasurement unit 2059 calculates Reference Signal Received Power (RSRP)and/or Reference Signal Received Quality (RSRQ) on the basis of the CRS,CSI-RS, or a detection signal, and outputs the calculated signal to theupper layer processing unit 201.

In accordance with the control from the control unit 203, thetransmission unit 207 performs transmission processing such as encoding,modulation, and multiplexing on the uplink control information and theuplink data input from the upper layer processing unit 201. For example,the transmission unit 207 generates and multiplexes an uplink channelsuch as the PUSCH or PUCCH, and/or an uplink reference signal, togenerate a transmission signal. Note that, the transmission processingin the transmission unit 207 is performed on the basis of a settingdefined in advance, or a setting or notification from the base stationdevice 1.

The encoding unit 2071 performs encoding on an HARQ indicator(HARQ-ACK), uplink control information, and uplink data input from thecontrol unit 203, by using a predetermined encoding system such as blockencoding, convolutional encoding, turbo encoding, or the like. Themodulation unit 2073 modulates an encoded bit input from the encodingunit 2071 with a predetermined modulation system such as BPSK, QPSK,16QAM, 64QAM, 256QAM, or the like. The uplink reference signalgeneration unit 2079 generates an uplink reference signal on the basisof the RRC parameter set in the terminal device 2, and the like. Themultiplexing unit 2075 multiplexes a modulation symbol of each channeland the uplink reference signal, and arranges them in a predeterminedresource element.

The wireless transmission unit 2077 performs, on the signal from themultiplexing unit 2075, processing such as conversion to a time domainsignal by Inverse Fast Fourier Transform (IFFT), addition of a guardinterval, generation of a baseband digital signal, conversion to ananalog signal, quadrature modulation, conversion of an intermediatefrequency signal to a high frequency signal (up convert), removal of anextra frequency component, power amplification, or the like, to generatea transmission signal. The transmission signal output from the wirelesstransmission unit 2077 is transmitted from the transmission/receptionantenna 209.

<Signaling of Control Information in the Present Embodiment>

The base station device 1 and the terminal device 2 each can use variousmethods for signaling (notification, broadcasting, setting) of controlinformation. Signaling of control information can be performed atvarious layers. Signaling of control information includes physical layersignaling that is signaling through a physical layer, RRC signaling thatis signaling through an RRC layer, MAC signaling that is signalingthrough a MAC layer, and the like. RRC signaling is dedicated RRCsignaling for notifying the terminal device 2 of unique controlinformation, or common RRC signaling for notifying the base stationdevice 1 of unique control information. Signaling used by an upper layerseen from the physical layer, such as RRC signaling or MAC signaling, isalso referred to as upper layer signaling.

RRC signaling is implemented by signaling an RRC parameter. MACsignaling is implemented by signaling a MAC control element. Physicallayer signaling is implemented by signaling downlink control information(DCI) or uplink control information (UCI). Physical layer signaling isalso referred to as DCI signaling, UCI signaling, PDCCH signaling, orPUCCH signaling. The RRC parameter and the MAC control element aretransmitted by using the PDSCH or PUSCH. The DCI is transmitted by usingthe PDCCH or EPDCCH. The UCI is transmitted by using the PUCCH or PUSCH.RRC signaling and MAC signaling are used for signaling semi-staticcontrol information, and also referred to as semi-static signaling.Physical layer signaling is used for signaling dynamic controlinformation, and also referred to as dynamic signaling. The DCI is usedfor PDSCH scheduling, PUSCH scheduling, or the like. The UCI is used forCSI reporting, HARQ-ACK reporting, and/or a scheduling request (SR).

<Details of Downlink Control Information in the Present Embodiment>

Notification of the DCI is performed by using a DCI format having afield defined in advance. The field defined in the DCI format is mappedwith a predetermined information bit. The DCI performs notification ofdownlink scheduling information, uplink scheduling information, sidelinkscheduling information, a non-periodic CSI reporting request, or anuplink transmission power command.

The DCI format monitored by the terminal device 2 is determined by atransmission mode set for each serving cell. In other words, part of theDCI format monitored by the terminal device 2 can differ depending onthe transmission mode. For example, the terminal device 2 in which thedownlink transmission mode 1 is set monitors the DCI format 1A and theDCI format 1. For example, the terminal device 2 in which the downlinktransmission mode 4 is set monitors the DCI format 1A and the DCI format2. For example, the terminal device 2 in which the uplink transmissionmode 1 is set monitors the DCI format 0. For example, the terminaldevice 2 in which the uplink transmission mode 2 is set monitors the DCIformat 0 and the DCI format 4.

Notification is not performed of a control region in which the PDCCH forperforming notification of DCI for the terminal device 2 is arranged,and the terminal device 2 detects the DCI for the terminal device 2 byblind decoding (blind detection). Specifically, the terminal device 2monitors a set of PDCCH candidates in the serving cell. Monitoring meansthat decoding is attempted with all monitored DCI formats for each ofthe PDCCHs in the set. For example, the terminal device 2 attempts todecode all aggregation levels, PDCCH candidates, and DCI formats thatmay be transmitted to the terminal device 2. The terminal device 2recognizes DCI (PDCCH) successfully decoded (detected) as the DCI(PDCCH) for the terminal device 2.

A cyclic redundancy check (CRC) is added to the DCI. The CRC is used forDCI error detection and DCI blind detection. The CRC (CRC parity bit) isscrambled with a radio network temporary identifier (RNTI). The terminaldevice 2 detects whether it is the DCI for the terminal device 2 on thebasis of the RNTI. Specifically, the terminal device 2 descrambles a bitcorresponding to the CRC with a predetermined RNTI, extracts the CRC,and detects whether the corresponding DCI is correct.

The RNTI is defined or set depending on a purpose and application of theDCI. The RNTI includes Cell-RNTI (C-RNTI), Semi Persistent SchedulingC-RNTI (SPS C-RNTI), System Information-RNTI (SI-RNTI), Paging-RNTI(P-RNTI), Random Access-RNTI (RA-RNTI), Transmit PowerControl-PUCCH-RNTI (TPC-PUCCH-RNTI), Transmit Power Control-PUSCH-RNTI(TPC-PUSCH-RNTI), Temporary C-RNTI, Multimedia Broadcast MulticastServices (MBMS)-RNTI (M-RNTI), eIMTA-RNTI, and CC-RNTI.

The C-RNTI and SPS C-RNTI each are an RNTI unique to the terminal device2 in the base station device 1 (cell), and an identifier for identifyingthe terminal device 2. The C-RNTI is used to schedule the PDSCH or PUSCHin a certain subframe. The SPS C-RNTI is used to activate or releaseperiodic scheduling of a resource for the PDSCH or PUSCH. A controlchannel including a CRC scrambled with the SI-RNTI is used to schedule aSystem Information Block (SIB). A control channel including a CRCscrambled with the P-RNTI is used to control paging. A control channelincluding a CRC scrambled with the RA-RNTI is used to schedule aresponse for the RACH. A control channel including a CRC scrambled withthe TPC-PUCCH-RNTI is used to perform power control of the PUCCH. Acontrol channel including a CRC scrambled with the TPC-PUSCH-RNTI isused to perform power control of the PUSCH. A control channel includinga CRC scrambled with the Temporary C-RNTI is used by a mobile stationdevice for which the C-RNTI is not set or recognized. A control channelincluding a CRC scrambled with the M-RNTI is used to schedule the MBMS.A control channel including a CRC scrambled with the eIMTA-RNTI is usedto perform notification of information regarding TDD UL/DL setting of aTDD serving cell, in dynamic TDD (eIMTA). A control channel (DCI)including a CRC scrambled with the CC-RNTI is used to performnotification of the setting of an occupied OFDM symbol, in a LAAsecondary cell. Note that, the DCI format may be scrambled with a newRNTI, not limited to the above RNTI.

Scheduling information (downlink scheduling information, uplinkscheduling information, sidelink scheduling information) includesinformation for performing scheduling, as frequency domain scheduling,on a resource block basis or a resource block group basis. The resourceblock group is a set of consecutive resource blocks and indicatesallocated resources for a terminal device to be scheduled. The size ofthe resource block group is determined depending on the systembandwidth.

<Details of Downlink Control Channel in the Present Embodiment>

The DCI is transmitted by using a control channel such as the PDCCH orEPDCCH. The terminal device 2 monitors a set of PDCCH candidates and/ora set of EPDCCH candidates of one or a plurality of activated servingcells set by RRC signaling. Here, monitoring refers to attempting todecode the PDCCH and/or EPDCCH in a set corresponding to all monitoredDCI formats.

The set of PDCCH candidates or the set of EPDCCH candidates is alsoreferred to as a search space. In the search space, a common searchspace (CSS) and a UE-specific search space (USS) are defined. The CSSmay be defined only for the search space for the PDCCH.

The common search space (CSS) is a search space set on the basis of aparameter unique to the base station device 1 and/or a parameter definedin advance. For example, the CSS is a search space commonly used by aplurality of terminal devices. Therefore, the base station device 1 mapsa common control channel in the plurality of terminal devices to theCSS, whereby the resource for transmitting a control channel is reduced.

The UE-specific search space (USS) is a search space set by using atleast a parameter unique to the terminal device 2. Therefore, the USS isa search space unique to the terminal device 2, and the base stationdevice 1 can individually transmit a control channel unique to theterminal device 2 by the USS. Therefore, the base station device 1 canefficiently map control channels unique to the plurality of terminaldevices.

The USS may be set to be commonly used by the plurality of terminaldevices. To set a common USS for the plurality of terminal devices, theparameter unique to the terminal device 2 is set to be the same valueamong the plurality of terminal devices. For example, a unit in whichthe same parameters are set among the plurality of terminal devices is acell, a transmission point, a group of predetermined terminal devices,or the like.

The search space for each aggregation level is defined by the set ofPDCCH candidates. Each PDCCH is transmitted by using a set of one ormore control channel elements (CCEs). The number of CCEs used for onePDCCH is also referred to as an aggregation level. For example, thenumber of CCEs used for one PDCCH is one, two, four, or eight.

The search space for each aggregation level is defined by the set ofEPDCCH candidates. Each EPDCCH is transmitted by using a set of one ormore enhanced control channel elements (ECCEs). The number of ECCEs usedfor one EPDCCH is also referred to as an aggregation level. For example,the number of ECCEs used for one EPDCCH is 1, 2, 4, 8, 16, or 32.

The number of PDCCH candidates or the number of EPDCCH candidates isdetermined on the basis of at least the search space and the aggregationlevel. For example, in the CSS, the numbers of PDCCH candidates ataggregation levels 4 and 8 are four and two, respectively. For example,in the USS, the numbers of PDCCH candidates in aggregations 1, 2, 4, and8 are six, six, two, and two, respectively.

Each ECCE includes a plurality of enhanced resource element groups(EREGs). The EREG is used to define mapping of the EPDCCH to theresource element. In each RB pair, 16 EREGs are defined, numbered from 0to 15. In other words, an EREG 0 to an EREG 15 are defined in each RBpair. In each RB pair, the EREG 0 to the EREG 15 are periodicallydefined, with priority given to the frequency direction, with respect toresource elements other than the resource element to which apredetermined signal and/or channel are mapped. For example, a resourceelement to which a demodulation reference signal associated with theEPDCCH transmitted on the antenna ports 107 to 110 is mapped is notdefined as the EREG

The number of ECCEs used for one EPDCCH depends on an EPDCCH format, andis determined on the basis of another parameter. The number of ECCEsused for one EPDCCH is also referred to as an aggregation level. Forexample, the number of ECCEs used for one EPDCCH is determined on thebasis of the number of resource elements that can be used for EPDCCHtransmission in one RB pair, a method of transmitting the EPDCCH, andthe like. For example, the number of ECCEs used for one EPDCCH is 1, 2,4, 8, 16, or 32. Furthermore, the number of EREGs used for one ECCE isdetermined on the basis of a type of the subframe and a type of a cyclicprefix, and is four or eight. As the method of transmitting the EPDCCH,distributed transmission and localized transmission are supported.

The EPDCCH can use distributed transmission or localized transmission.Distributed transmission and localized transmission differ from eachother in mapping of the ECCE to the EREG and the RB pair. For example,in distributed transmission, one ECCE is configured by using EREGs of aplurality of RB pairs. In localized transmission, one ECCE is configuredby using EREGs of one RB pair.

The base station device 1 performs setting regarding the EPDCCH for theterminal device 2. The terminal device 2 monitors a plurality of EPDCCHson the basis of the setting from the base station device 1. A set of RBpairs for which the terminal device 2 monitors the EPDCCH can be set.The set of RB pairs is also referred to as an EPDCCH set or anEPDCCH-PRB set. One or more EPDCCH sets can be set for one terminaldevice 2. Each EPDCCH set includes one or more RB pairs. Furthermore,the setting regarding the EPDCCH can be performed individually for eachEPDCCH set.

The base station device 1 can set a predetermined number of EPDCCH setsfor the terminal device 2. For example, up to two EPDCCH sets can be setas an EPDCCH set 0 and/or an EPDCCH set 1. Each of the EPDCCH sets caninclude a predetermined number of RB pairs. Each EPDCCH set constitutesone set of a plurality of ECCEs. The number of ECCEs included in oneEPDCCH set is determined on the basis of the number of RB pairs set asthe EPDCCH set and the number of EREGs used in one ECCE. In a case wherethe number of ECCEs included in one EPDCCH set is N, each EPDCCH setconstitutes ECCEs numbered 0 to N-1. For example, in a case where thenumber of EREGs used in one ECCE is four, an EPDCCH set including fourRB pairs constitutes 16 ECCEs.

<Details of Resource Allocation in the Present Embodiment>

The base station device 1 can use a plurality of methods as a method ofresource allocation of the PDSCH and/or PUSCH to the terminal device 2.The method of resource allocation includes dynamic scheduling,semi-persistent scheduling, multi-subframe scheduling, and crosssubframe scheduling.

In dynamic scheduling, one DCI performs resource allocation in onesubframe. Specifically, the PDCCH or EPDCCH in a certain subframeperforms scheduling for the PDSCH in the subframe. The PDCCH or EPDCCHin a certain subframe performs scheduling for the PUSCH in apredetermined subframe after the subframe.

In multi-subframe scheduling, one DCI performs resource allocation inone or more subframes. Specifically, the PDCCH or EPDCCH in a certainsubframe performs scheduling for the PDSCH in one or more subframesafter a predetermined number of subframes from the subframe. The PDCCHor EPDCCH in a certain subframe performs scheduling for the PUSCH in oneor more subframes after a predetermined number of subframes from thesubframe. The predetermined number can be an integer greater than orequal to zero. The predetermined number may be defined in advance or maybe determined on the basis of physical layer signaling and/or RRCsignaling. In multi-subframe scheduling, consecutive subframes may bescheduled, or subframes having a predetermined period may be scheduled.The number of subframes to be scheduled may be defined in advance, ormay be determined on the basis of physical layer signaling and/or RRCsignaling.

In cross subframe scheduling, one DCI performs resource allocation inone subframe. Specifically, the PDCCH or EPDCCH in a certain subframeperforms scheduling for the PDSCH in one subframe after a predeterminednumber of subframes from the subframe. The PDCCH or EPDCCH in a certainsubframe performs scheduling for the PUSCH in one subframe after apredetermined number of subframes from the subframe. The predeterminednumber can be an integer greater than or equal to zero. Thepredetermined number may be defined in advance or may be determined onthe basis of physical layer signaling and/or RRC signaling. In crosssubframe scheduling, consecutive subframes may be scheduled, orsubframes having a predetermined period may be scheduled.

In semi-persistent scheduling (SPS), one DCI performs resourceallocation in one or more subframes. In a case where informationregarding the SPS is set by RRC signaling and the PDCCH or EPDCCH forenabling the SPS is detected, the terminal device 2 enables processingfor the SPS, and receives a predetermined PDSCH and/or PUSCH on thebasis of the setting for the SPS. In a case where the PDCCH or EPDCCHfor releasing the SPS is detected when the SPS is enabled, the terminaldevice 2 releases (disables) the SPS and stops reception of thepredetermined PDSCH and/or PUSCH. The release of the SPS may beperformed on the basis of a case where a predetermined condition issatisfied. For example, the SPS is released in a case where apredetermined number of empty transmission data is received. Emptytransmission of data for releasing the SPS corresponds to MAC ProtocolData Unit (PDU) including zero MAC Service Data Unit (SDU).

Information regarding the SPS by RRC signaling includes an SPS C-RNTIthat is an RNTI of the SPS, information regarding a period (interval) tobe scheduled for the PDSCH, information regarding a period (interval) tobe scheduled for the PUSCH, information regarding a setting forreleasing the SPS, and/or an HARQ process number in the SPS. The SPS issupported only for the primary cell and/or the primary secondary cell.

<HARQ in the Present Embodiment>

In the present embodiment, an HARQ has various features. The HARQtransmits and retransmits a transport block. In the HARQ, apredetermined number of processes (HARQ processes) are used (set), andeach of the processes operates independently in a stop-and-wait manner.

In the downlink, the HARQ is asynchronous and operates adaptively. Inother words, in the downlink, retransmission is always scheduled throughthe PDCCH. Uplink HARQ-ACK (response information) corresponding todownlink transmission is transmitted on the PUCCH or PUSCH. In thedownlink, the PDCCH performs notification of an HARQ process numberindicating its HARQ process, and information indicating whether thetransmission is initial transmission or retransmission.

In the uplink, the HARQ operates synchronously or asynchronously.Downlink HARQ-ACK (response information) corresponding to uplinktransmission is transmitted on the PHICH, PDSCH or PDCCH. In the uplinkHARQ, operation of a terminal device is determined on the basis of theHARQ feedback received by the terminal device and/or the PDCCH receivedby the terminal device. For example, in a case where the PDCCH is notreceived and the HARQ feedback is ACK, the terminal device does notperform transmission (retransmission) and holds data in the HARQ buffer.In that case, the PDCCH may be transmitted to resume retransmission.Furthermore, for example, in a case where the PDCCH is not received andthe HARQ feedback is NACK, the terminal device performs retransmissionnon-adaptively in a predetermined uplink subframe. Furthermore, forexample, in a case where the PDCCH is received, the terminal deviceperforms transmission or retransmission on the basis of the contentreceived via the PDCCH regardless of the content of the HARQ feedback.

Note that, in the uplink, in a case where a predetermined condition(setting) is satisfied, the HARQ may operate only asynchronously. Inother words, the downlink HARQ-ACK is not transmitted, andretransmission in the uplink may always be scheduled through the PDCCH.

In the HARQ-ACK reporting, the HARQ-ACK indicates ACK, NACK, or DTX. Ina case where the HARQ-ACK is ACK, it indicates that the transport block(codeword, channel) corresponding to the HARQ-ACK is correctly received(decoded). In a case where the HARQ-ACK is NACK, it indicates that thetransport block (codeword, channel) corresponding to the HARQ-ACK is notcorrectly received (decoded). In a case where the HARQ-ACK is DTX, itindicates that the transport block (codeword, channel) corresponding tothe HARQ-ACK does not exist (is not transmitted).

Furthermore, transmission (notification) of the HARQ-ACK (responseinformation) can be performed by using various processing units. Forexample, the HARQ-ACK can be transmitted for each transport block,codeword, code block, or code block group. Here, the transport block andcodeword can be processing units for the modulation system and/orencoding rate. One data channel can transmit up to two transport blocksand codewords. Furthermore, the code block can be a processing unit ofan error correction code such as a turbo code, a convolutional code, aLow Density Parity Check (LDPC) code, or a Polar code. One transportblock includes one or more codewords. The maximum bit depth in one codeblock can be defined or set. The maximum bit depth may be determineddepending on the error correction code used, the size of the codeword,and/or the type of the channel. Furthermore, the code block groupincludes one or more code blocks. In that case, one transport blockincludes one or more code block groups. The number of code blocksincluded in the code block group can be defined or set uniquely for thebase station, the cell, and/or the terminal. The number may bedetermined depending on the error correction code used, the size of thecodeword, and/or the type of the channel.

In each of the downlink and uplink, a predetermined number of HARQprocesses are set (defined). For example, in FDD, up to eight HARQprocesses are used for each serving cell. Furthermore, for example, inTDD, the maximum number of HARQ processes is determined by theuplink/downlink setting. The maximum number of HARQ processes may bedetermined on the basis of round trip time (RTT). For example, in a casewhere the RTT is 8 TTIs, the maximum number of HARQ processes can beeight.

In the present embodiment, HARQ information includes at least a new dataindicator (NDI) and transport block size (TBS). The NDI is informationindicating whether the transport block corresponding to the HARQinformation is initial transmission or retransmission. The TBS is thesize of the transport block. The transport block is a block of data in atransport channel (transport layer), and can be a unit for performingthe HARQ. In DL-SCH transmission, the HARQ information further includesan HARQ process ID (HARQ process number). In UL-SCH transmission, theHARQ information further includes a redundancy version (RV) that isinformation for specifying an information bit and a parity bit afterencoding for the transport block. In the case of spatial multiplexing inthe DL-SCH, the HARQ information includes a set of the NDI and TBS foreach transport block.

<Frame Configuration (Time Domain) of NR in the Present Embodiment>

In a frame configuration of NR, definition can be made by the subframe,the slot, and the mini-slot. The subframe includes 14 symbols, and canbe used in the definition of the frame configuration in a referencesubcarrier interval (defined subcarrier interval). The slot is a symbolsection in the subcarrier interval used for communication, and includes7 or 14 symbols. The number of symbols constituting one slot can be setfrom the base station device 1 uniquely for the cell or uniquely for theterminal device. The mini-slot can include symbols fewer than symbolsconstituting the slot. For example, one mini-slot includes one to sixsymbols, and can be set from the base station device 1 uniquely for thecell or uniquely for the terminal device. Both the slot and themini-slot are used as units of time domain resources for communication.For example, the slot is used for communication for eMBB and mMTC, andthe mini-slot is used for communication for URLLC. Furthermore, names ofthe slot and the mini-slot do not have to be distinguished from eachother.

FIG. 10 illustrates an example of the frame configuration of NR in thepresent embodiment. FIG. 10 illustrates a frame configuration in apredetermined frequency domain. For example, the frequency domainincludes the resource block, subband, system bandwidth, or the like.Therefore, the frame configuration as illustrated in FIG. 10 can befrequency-multiplexed and/or spatially multiplexed.

In NR, one slot includes downlink communication, a guard section (guardperiod: GP), and/or downlink communication. The downlink communicationincludes downlink channels such as the NR-PDCCH and/or the NR-PDSCH.Furthermore, the downlink transmission includes a reference signalassociated with the NR-PDCCH and/or the NR-PDSCH. The uplinkcommunication includes uplink channels such as the NR-PUCCH and/or theNR-PUSCH. Furthermore, the downlink communication includes a referencesignal associated with the NR-PUCCH and/or the NR-PUSCH. The GP is atime domain where nothing is transmitted. For example, the GP is used toadjust a time for switching from reception of the downlink communicationto transmission of the uplink communication in the terminal device 2, aprocessing time in the terminal device 2, and/or a transmission timingof the uplink communication.

As illustrated in FIG. 10, NR can use various frame configurations. FIG.10(a) includes the NR-PDCCH, NR-PDSCH, GP and NR-PUCCH. The NR-PDCCHperforms notification of allocation information on the NR-PDSCH, and theNR-PUCCH in the same slot performs notification of the HARQ-ACK for thereceived NR-PDSCH. FIG. 10(b) includes the NR-PDCCH, GP, and NR-PUSCH.The NR-PDCCH performs notification of allocation information on theNR-PUSCH, and the NR-PUSCH is transmitted on an allocated resource inthe same slot. The frame configurations as illustrated in FIGS. 10(a)and 10(b) are also referred to as Self-contained frames because thedownlink communication and the uplink communication are completed in thesame slot.

FIGS. 10(c) to 10(g) are slots including only the downlink communicationor only the uplink communication. In FIG. 10(c), the NR-PDSCH can bescheduled by the NR-PDCCH in the same slot. In FIGS. 10(d) and 10(e),the NR-PDSCH and the NR-PUSCH each can be scheduled by the NR-PDCCHmapped to a different slot, or by RRC signaling or the like. In FIG.10(h), the entire slot is the guard section and used as a region notcommunicated.

<Outline of Uplink Signal Waveform in the Present Embodiment>

In the present embodiment, a plurality of types of signal waveforms isdefined in the uplink. For example, two uplink signal waveforms can bedefined, and set as a first signal waveform and a second signalwaveform, respectively. In the present embodiment, the first signalwaveform is Cyclic Prefix-Orthogonal Frequency Division Multiplexing(CP-OFDM), and the second signal waveform is Single Carrier-FrequencyDivision Multiple Access (SC-FDMA). Furthermore, the second signalwaveform is also referred to as Discrete FourierTransform-Spread-Orthogonal Frequency Division Multiplexing(DFT-s-OFDM).

That is, the first signal waveform is a multicarrier signal, and thesecond signal waveform is a single carrier signal. Furthermore, thefirst signal waveform is the same as the downlink signal waveform in LTEand NR, and the second signal waveform is the same as the uplink signalwaveform in LTE.

These signal waveforms can differ from each other in terms of powerefficiency, transmission efficiency, transmission (generation) method,reception method, resource mapping, and the like. For example, thesecond signal waveform can reduce a Peak-to-Average Power Ratio (PAPR)compared to the first signal waveform, thereby being superior in powerefficiency. Furthermore, the first signal waveform canfrequency-multiplex the reference signal with data in the frequencydirection, thereby being superior in terms of transmission efficiencycompared to the second signal waveform. Furthermore, in a case where itis necessary to perform frequency domain equalization in receptionprocessing for the second signal waveform, the second signal waveformhas a high load of the reception processing compared to the first signalwaveform. Furthermore, the first signal waveform has a narrow subcarrierinterval compared to the second signal waveform, thereby beingsusceptible to phase noise particularly in a high frequency band.

<Overview of Reliability Control of Response Information to Data in thePresent Embodiment>

In the present embodiment, response information (HARQ-ACK) to data istransmitted by a predetermined transmission method regardingreliability. The predetermined transmission method can be determineddepending on reliability priority for the data.

Note that, in the following description, the data includes a datachannel, and the data channel includes downlink channels such as thePDSCH and uplink channels such as the PUSCH. Furthermore, the controlchannel is a physical channel for transmitting the response informationto the data, and the control channel includes uplink channels such asthe PUCCH and PUSCH, and downlink channels such as the PDCCH, PHICH, andPDSCH. In other words, contents described in the present embodiment canbe implemented in both a case where the base station device transmitsthe data channel and the terminal device transmits the control channel,and a case where the terminal device transmits the data channel and thebase station device transmits the control channel.

Furthermore, as described above, the response information can betransmitted for each transport block, codeword, code block, or codeblock group, but for the sake of simplicity, in the followingdescription, the data and the response information are described as achannel or information for each slot.

FIG. 11 illustrates an example of reliability control of the responseinformation to the data. In the figure, five slots are illustrated fromslot numbers #n to #n+4. Furthermore, in a case where a data channel ina predetermined slot is transmitted, the response information in thedata channel is transmitted on a control channel of the next slot.Therefore, control channels in the slots from the slot numbers #n to#n+4 respectively transmit pieces of the response information to thedata in the slots from slot numbers #n−1 to #n+3.

These pieces of the response information each are controlled regardingthe reliability priority, and transmitted by a predeterminedtransmission method determined depending on the reliability priority.

The reliability priority and the predetermined transmission methodregarding the reliability will be described later. Furthermore, thepredetermined transmission method regarding the reliability is alsosimply referred to as a predetermined transmission method.

<Multiplexing of Response Information Repeatedly Transmitted in thePresent Embodiment>

The response information to the data can be repeatedly transmitted on aplurality of control channels. Furthermore, in a certain control channeland/or slot, pieces of the response information to the data in aplurality of slots can be multiplexed. FIG. 12 illustrates an example.

In other words, in a control channel of a predetermined slot, apredetermined number of pieces of the response information to the datain the predetermined number of slots before the predetermined slot ismultiplexed. Moreover, any of the predetermined number of pieces of theresponse information is repeatedly transmitted a plurality of times ondifferent control channels. Furthermore, the predetermined number ofpieces of the response information multiplexed in the predetermined slotis transmitted on one uplink physical channel.

Furthermore, these pieces of the response information each arecontrolled regarding the reliability priority, and transmitted by apredetermined transmission method determined depending on thereliability priority. The control may be performed for each slot, or maybe performed for each piece of the response information multiplexed inthe same slot.

In the example of FIG. 12, the control channel in a certain slotmultiplexes and transmits pieces of the response information to the datain three slots closest to the slot.

<Reliability Priority in the Present Embodiment>

In the present embodiment, the reliability priority is priorityregarding the reliability of the response information. In the presentembodiment, the reliability priority is also simply referred to aspriority. Furthermore, the reliability priority may be regarded simplyas a parameter or a value.

The reliability priority can be controlled in various units. Forexample, the reliability priority can be controlled in units of theresponse information, predetermined response information group, controlchannel, slot, mini-slot, subframe, radio frame, cell, and/or basestation.

Control of the reliability priority (reliability prioritization) isperformed depending on various factors and/or parameters. A specificcontrol method is any one or a combination of methods described below.

As an example of a reliability priority control method, the reliabilitypriority is determined depending on the order of the slot in which thedata is received (transmitted). In other words, the reliability priorityis given by a reception (transmission) timing of the data. For example,regarding the response information for the slot that is temporally new,the reliability priority is set higher.

As another example of the reliability priority control method, thereliability priority is determined on the basis of an HARQ timingreceived. Here, the HARQ timing is a timing of the data transmitted andthe response information to the data, and notification of the HARQtiming can be performed by RRC signaling and/or PDCCH signaling. Inother words, the reliability priority is given by at least atransmission timing of the response information to reception of thedata. For example, for the response information having a short HARQtiming, the reliability priority is set higher. For example, in a casewhere the data and its response information are transmitted and receivedin the same slot, the reliability priority of the response informationis set higher.

As another example of the reliability priority control method, thereliability priority is determined on the basis of the number ofrepetitions of the response information. In other words, the reliabilitypriority is given by at least the number of times of repeatedtransmission of the response information. For example, for the responseinformation having a large number of times of repeated transmission sofar, the reliability priority is set higher. Furthermore, for example,for the response information having a large number of repetitions of thesetting or notification, the reliability priority is set higher.

As another example of the reliability priority control method, thereliability priority is determined on the basis of the type of thechannel corresponding to the response information. For example, for theresponse information to the control channel, the reliability priority isset higher, and for the response information to the data channel, thereliability priority is set lower.

As another example of the reliability priority control method, thereliability priority is received or set from the base station. Forexample, the reliability priority is determined for each data channel,and included in control information for allocating the data channel. Inother words, the reliability priority is given by at least the controlinformation for the data channel.

As another example of the reliability priority control method, thereliability priority is determined on the basis of the size of the data.For example, the reliability priority is set higher as the size of thedata is increased. For example, the size of the data is the number ofresource blocks, the size (bit depth) of the transport block, the size(bit depth) of the code block, or the size (bit depth) of the code blockgroup.

As another example of the reliability priority control method, thereliability priority is determined on the basis of the HARQ process. Forexample, the reliability priority is set higher as the number of HARQprocesses decreases. Furthermore, for example, the reliability priorityis set higher in the case of a predetermined HARQ process number. Thepredetermined HARQ process number is 0.

<Predetermined Transmission Method Regarding Reliability in the PresentEmbodiment>

In the present embodiment, the predetermined transmission methodregarding the reliability is controlled on the basis of the reliabilitypriority. For example, the response information having a highreliability priority is transmitted by using a highly reliabletransmission method.

An example of the predetermined transmission method regarding thereliability is a method regarding repeated transmission. For example,the response information having a high reliability priority istransmitted by increasing the number of times of repeated transmission.This repeated transmission can be performed in the frequency directionand/or in the time direction. Note that, this repeated transmission maybe performed on each individual control channel or may be performed inthe same control channel.

FIG. 13 is a diagram illustrating an example of reliability controlregarding the number of times of repeated transmission. The number oftimes of repeated transmission is determined on the basis of thereliability priority, for each data. In the example of FIG. 13, thenumbers of times of repeated transmission for response information ofdata A, B, and C are twice, three times, and once, respectively. In thiscase, the response information of the data A is transmitted on thecontrol channel of the slot #n+1, the response information of the data Aand the response information of the data B are multiplexed andtransmitted on the control channel of the slot #n+2, the responseinformation of the data B is transmitted on the control channel of theslot #n+3, and the response information of the data B and the responseinformation of the data C are multiplexed and transmitted on the controlchannel of the slot #n+4.

Another example of the predetermined transmission method regarding thereliability is a method regarding the error correction code. Forexample, the response information having a high reliability priority istransmitted with a low encoding rate (with a high encoding gain) in theerror correction code. Furthermore, for example, the responseinformation having a high reliability priority is transmitted by usingan error correction code having a high encoding gain.

Another example of the predetermined transmission method regarding thereliability is a method regarding the transmission power. For example,the response information having a high reliability priority istransmitted with high transmission power. The transmission power isdetermined on the basis of at least an index defined in advance and/oran offset value defined in advance, and the index and/or the offsetvalue are determined on the basis of the reliability priority.

Another example of the predetermined transmission method regarding thereliability is a method regarding the modulation system. For example,the response information having a high reliability priority istransmitted by using a modulation system having low modulationmultilevel number (modulation order). Specifically, the modulationsystem includes BPSK, QPSK, 16QAM, 64QAM, 256QAM, and 1024QAM inascending order of the modulation multilevel number. Furthermore, BPSKmay shift the phase by π/2 for each symbol.

Another example of the predetermined transmission method regarding thereliability is a method regarding resource element mapping. For example,the response information having a high reliability priority istransmitted by being mapped to a highly reliable resource element. Thehighly reliable resource element is a resource element around a resourceelement to which the reference signal is mapped. Specifically, theresponse information having a high reliability priority is transmittedby being mapped to a resource element adjacent to the resource elementto which the reference signal is mapped. As a result, the responseinformation having a high reliability priority has a high accuracy oftransmission path estimation on the reception side.

Another example of the predetermined transmission method regarding thereliability is a method regarding the size of the resource used fortransmission. For example, the response information having a highreliability priority is transmitted by using a resource having a largesize. The resource here includes the number of PRBs, the number ofsymbols, and/or the number of resource elements. As a result, theresponse information having a high reliability priority can betransmitted with a high encoding gain.

Another example of the predetermined transmission method regarding thereliability is a method regarding the signal waveform. For example, theresponse information having a high reliability priority is transmittedby using a highly reliable signal waveform. The reliability of thesignal waveform may be determined in terms of the PAPR. Specifically,the highly reliable signal waveform is the second signal waveform.

Another example of the predetermined transmission method regarding thereliability is a method regarding the type of control channel used fortransmission. For example, the response information having a highreliability priority is transmitted on a first control channel, and theresponse information having a low reliability priority is transmitted ona second control channel. A difference between the first control channeland the second control channel is the number of symbols that can be usedfor transmission. The first control channel is transmitted by using aresource of four or more symbols, and the second control channel istransmitted by using a resource of one or two symbols. The first controlchannel is also referred to as a long PUCCH, and the second controlchannel is also referred to as a short PUCCH. Furthermore, the firstcontrol channel may be mapped to any of the slots, and the secondcontrol channel may be mapped to only the last of the slots. As aresult, the response information having a high reliability priority canincrease the size of the resource used for transmission, and can betransmitted with a high encoding gain.

<Multiplexing Number of Response Information in the Present Embodiment>

As described above, in the present embodiment, one or more pieces of theresponse information can be multiplexed in a certain slot and/or controlchannel. The multiplexing number may be defined in advance or may be setfrom the base station. Furthermore, the multiplexing number is thenumber of pieces of the response information actually multiplexed, andcan be determined on the basis of various conditions, parameters, and/orfactors.

For example, the multiplexing number of the response information isdetermined on the basis of at least the maximum multiplexing number ofthe response information. The maximum multiplexing number of theresponse information may be defined in advance or may be set from thebase station.

As an example of a method of determining the multiplexing number of theresponse information, the multiplexing number of the responseinformation is the maximum multiplexing number of the responseinformation regardless of actual data reception. At this time, theresponse information without actual data reception can be DTX.

For example, in a case where the maximum multiplexing number of theresponse information is set to three, using the example of FIG. 12,multiplexing is considered of the response information in the controlchannel of the slot #n+3. In a case where data is received in the slot#n+1 and no data is received in the slots #n and #n+2, three pieces ofthe response information (one ACK or NACK, and two DTXs) are multiplexedin the control channel of the slot #n+3.

Furthermore, in a certain control channel, in a case where all pieces ofthe response information to be multiplexed are DTX, the control channeldoes not have to be transmitted.

As another example of the method of determining the multiplexing numberof the response information, the multiplexing number of the responseinformation is determined on the basis of the number of pieces of theresponse information of the data actually received and the maximummultiplexing number of the response information.

In a case where the number of pieces of the response information of thedata actually received is equal to or less than the maximum multiplexingnumber of the response information, the multiplexing number of theresponse information is the number of pieces of the response informationof the data actually received.

In a case where the number of pieces of the response information of thedata actually received exceeds the maximum multiplexing number of theresponse information, the multiplexing number of the responseinformation is set equal to or less than the maximum multiplexing numberof the response information. Furthermore, in that case, a method ofreducing the number of pieces of the response information of the dataactually received to the maximum multiplexing number of the responseinformation can be performed by using various methods.

As an example of the reduction method, bundling may be used of theresponse information having a low reliability priority. Here, thebundling of the response information is to convert a plurality of piecesof the response information into one response information by logicalmultiplication, and in a case where all pieces of the responseinformation to be bundled are ACKs, the information becomes ACK.

As an example of the reduction method, the response information having alow reliability priority may be dropped. Here, the drop of the responseinformation is not to transmit the response information. Furthermore,the drop of the response information may be determined, further on thebasis of the number of times of repeated transmission. For example, thedrop of the response information is preferentially performed on theresponse information having a large number of times of repeatedtransmission so far.

Furthermore, in a case where the number of pieces of the responseinformation of the data actually received exceeds the maximummultiplexing number of the response information, transmission may beperformed by changing the resource and/or channel for transmitting theresponse information. In other words, in a case where the number ofpieces of the response information of the data actually received isequal to or less than the maximum multiplexing number of the responseinformation (a set predetermined value), those pieces of the responseinformation are transmitted on the second control channel (short PUCCH).In a case where the number of pieces of the response information of thedata actually received exceeds the maximum multiplexing number of theresponse information (the set predetermined value), those pieces of theresponse information are transmitted on the first control channel (longPUCCH).

Furthermore, the terminal device does not have to assume a case wherethe number of pieces of the response information of the data actuallyreceived exceeds the maximum multiplexing number of the responseinformation. In other words, the base station device performs control(scheduling) on the terminal device so that the number of pieces of theresponse information of the data actually received does not exceed themaximum multiplexing number of the response information.

<Resource of Control Channel for Tranmitting Response Information in thePresent Embodiment>

As described above, in the present embodiment, the response informationis transmitted on a predetermined control channel or the like. Aresource of the control channel used for transmission of the responseinformation is determined by a predetermined method. Here, the resourceof the control channel includes a physical resource or a logicalresource. The resource of the control channel is determined by any oneor a combination of methods described below.

As an example of a method of determining the resource of the controlchannel, notification of the resource of the control channel isperformed by RRC signaling and/or DCI signaling. For example, aplurality of candidates is set by RRC signaling for the resource of thecontrol channel, and DCI signaling performs notification of controlinformation for making a selection from the candidates.

As another example of the method of determining the resource of thecontrol channel, the resource of the control channel is determined onthe basis of data corresponding to the response information transmittedon the control channel. For example, information (for example, the firstCCE number) is used on the resource of the PDCCH for performingnotification of allocation information of the data. Furthermore, in acase where a plurality of pieces of the response information ismultiplexed, the resource of the control channel may be determined onthe basis of the temporally latest reception data or the reception datahaving the highest reliability priority.

As another example of the control channel resource determination method,the control channel resource is determined on the basis of themultiplexing number of the response information. For example, in a casewhere the multiplexing number of the response information is equal to orless than a predetermined value, the resource of the control channel isa first resource, and in a case where the multiplexing number of theresponse information exceeds the predetermined value, the resource ofthe control channel is a second resource. The predetermined value may bedefined in advance or may be set from the base station. Furthermore, thefirst resource and the second resource differ from each other in themultiplexing number of the response information that can be transmitted.

<Details of Repeated Transmission of Response Information in the PresentEmbodiment>

As described above, in the present embodiment, the response informationcan be repeatedly transmitted. The number of repeated transmissions maybe determined on the basis of the reliability priority, as describedabove. Furthermore, notification of the number of times of repeatedtransmission may be performed by RRC signaling and/or DCI signaling.

Furthermore, in a case where retransmission of the data is performedwhile repeated transmission is performed of response information tocertain data, the repeated transmission of the response information isstopped after a predetermined slot. The data can be identified by theHARQ process number. The predetermined slot is a slot in which the datais retransmitted, a slot next to the slot in which the data isretransmitted, or a slot after a predetermined number from the slot inwhich the data is retransmitted.

<Application to Sidelink of Uplink Signal Waveform in the PresentEmbodiment>

The contents described in the present embodiment can also be applied tothe sidelink communication. Reliability of the response information tothe data in the sidelink communication of NR can be controlled by themethod described in the present embodiment. In other words, in thedescription of the present embodiment, the uplink can be read as thesidelink.

In addition to the above, reliability control of the responseinformation to the data in the sidelink can be set independently foreach predetermined resource pool.

<Terminal Capability Information Regarding Uplink Signal Waveform in thePresent Embodiment>

In the present embodiment, the terminal device 2 can notify the basestation device 1 of terminal capability information indicating afunction or capability of the terminal device 2. The terminal capabilityinformation allows the base station device 1 to recognize the functionor capability of the terminal device 2, and is used for setting andscheduling of the terminal device 2. For example, the terminalcapability information includes information indicating a function orcapability regarding the reliability control of the response informationto the data.

APPLICATION EXAMPLE

[Application Example of Base Station]

First Application Example

FIG. 14 is a block diagram illustrating a first example of a schematicconfiguration of an eNB to which a technology according to the presentdisclosure can be applied. An eNB 800 includes one or more antennas 810,and a base station device 820. The antennas 810 and the base stationdevice 820 can be connected to each other via RF cables.

Each of the antennas 810 includes a single or a plurality of antennaelements (for example, a plurality of antenna elements constituting aMIMO antenna), and is used for transmission/reception of a wirelesssignal by the base station device 820. The eNB 800 may include aplurality of the antennas 810 as illustrated in FIG. 14, and theplurality of antennas 810 may respectively correspond to, for example, aplurality of frequency bands used by the eNB 800. Note that, althoughFIG. 14 illustrates an example in which the eNB 800 includes theplurality of antennas 810, the eNB 800 may include a single antenna 810.

The base station device 820 includes a controller 821, a memory 822, anetwork interface 823, and a wireless communication interface 825.

The controller 821 may be, for example, a CPU or a DSP, and operatesvarious functions of an upper layer of the base station device 820. Forexample, the controller 821 generates a data packet from data in asignal processed by the wireless communication interface 825, andtransfers the generated packet via the network interface 823. Thecontroller 821 may generate a bundled packet by bundling data from aplurality of baseband processors, and transfer the generated bundledpacket. Furthermore, the controller 821 may have a logical function ofexecuting control such as radio resource control, radio bearer control,mobility management, admission control, or scheduling. Furthermore, thecontrol may be executed in cooperation with a neighboring eNB or corenetwork node. The memory 822 includes a RAM and a ROM, and stores aprogram executed by the controller 821, and various control data (forexample, terminal list, transmission power data, and scheduling data).

The network interface 823 is a communication interface for connectingthe base station device 820 to a core network 824. The controller 821may communicate with a core network node or another eNB via the networkinterface 823. In that case, the eNB 800 and the core network node orthe other eNB may be connected to each other by a logical interface (forexample, an S1 interface or an X2 interface). The network interface 823may be a wired communication interface, or may be a wirelesscommunication interface for a wireless backhaul. In a case where thenetwork interface 823 is a wireless communication interface, the networkinterface 823 may use a higher frequency band for wireless communicationthan a frequency band used by the wireless communication interface 825.

The wireless communication interface 825 supports any cellularcommunication system such as Long Term Evolution (LTE) or LTE-Advanced,and provides a wireless connection to a terminal located in a cell ofthe eNB 800 via the antenna 810. The wireless communication interface825 can typically include a baseband (BB) processor 826 and an RFcircuit 827, and the like. The BB processor 826 may perform, forexample, encoding/decoding, modulation/demodulation,multiplexing/demultiplexing, and the like, and executes various types ofsignal processing of each layer (for example, L1, Medium Access Control(MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol(PDCP)). The BB processor 826 may have some or all of the logicalfunctions described above instead of the controller 821. The BBprocessor 826 may be a module including a memory that stores acommunication control program, a processor that executes the program,and a related circuit, and the function of the BB processor 826 may bechangeable by update of the program. Furthermore, the module may be acard or a blade inserted into a slot of the base station device 820, ormay be a chip mounted on the card or the blade. On the other hand, theRF circuit 827 may include a mixer, a filter, an amplifier, and thelike, and transmits and receives the wireless signal via the antenna810.

The wireless communication interface 825 may include a plurality of theBB processors 826 as illustrated in FIG. 14, and the plurality of BBprocessors 826 may respectively correspond to, for example, theplurality of frequency bands used by the eNB 800. Furthermore, thewireless communication interface 825 may include a plurality of the RFcircuits 827 as illustrated in FIG. 14, and the plurality of RF circuits827 may respectively correspond to, for example, the plurality ofantenna elements. Note that, although FIG. 14 illustrates an example inwhich the wireless communication interface 825 includes the plurality ofBB processors 826 and the plurality of RF circuits 827, the wirelesscommunication interface 825 may include a single BB processor 826 or asingle RF circuit 827.

Second Application Example

FIG. 15 is a block diagram illustrating a second example of theschematic configuration of the eNB to which the technology according tothe present disclosure can be applied. An eNB 830 includes one or moreantennas 840, a base station device 850, and an RRH 860. The antennas840 and the RRH 860 can be connected to each other via RF cables.Furthermore, the base station device 850 and the RRH 860 can beconnected to each other via a high speed line such as an optical fibercable.

Each of the antennas 840 includes a single or a plurality of antennaelements (for example, a plurality of antenna elements constituting aMIMO antenna), and is used for transmission/reception of a wirelesssignal by the RRH 860. The eNB 830 may include a plurality of theantennas 840 as illustrated in FIG. 15, and the plurality of antennas840 may respectively correspond to, for example, a plurality offrequency bands used by the eNB 830. Note that, although FIG. 15illustrates an example in which the eNB 830 includes the plurality ofantennas 840, the eNB 830 may include a single antenna 840.

The base station device 850 includes a controller 851, a memory 852, anetwork interface 853, a wireless communication interface 855, and aconnection interface 857. The controller 851, the memory 852 and thenetwork interface 853 are similar to the controller 821, the memory 822,and the network interface 823 described with reference to FIG. 14.

The wireless communication interface 855 supports any cellularcommunication system such as LTE or LTE-Advanced, and provides awireless connection to a terminal located in a sector corresponding tothe RRH 860 via the RRH 860 and the antenna 840. The wirelesscommunication interface 855 can typically include a BB processor 856,and the like. The BB processor 856 is similar to the BB processor 826described with reference to FIG. 14 except that the BB processor 856 isconnected to the RF circuit 864 of the RRH 860 via the connectioninterface 857. The wireless communication interface 855 may include aplurality of the BB processors 856 as illustrated in FIG. 15, and theplurality of BB processors 856 may respectively correspond to, forexample, the plurality of frequency bands used by the eNB 830. Notethat, although FIG. 15 illustrates an example in which the wirelesscommunication interface 855 includes the plurality of BB processors 856,the wireless communication interface 855 may include a single BBprocessor 856.

The connection interface 857 is an interface for connecting the basestation device 850 (wireless communication interface 855) to the RRH860. The connection interface 857 may be a communication module forcommunication on the high speed line that connects the base stationdevice 850 (wireless communication interface 855) and the RRH 860 toeach other.

Furthermore, the RRH 860 includes a connection interface 861 and awireless communication interface 863.

The connection interface 861 is an interface for connecting the RRH 860(wireless communication interface 863) to the base station device 850.The connection interface 861 may be a communication module forcommunication on the high speed line.

The wireless communication interface 863 transmits and receives thewireless signal via the antenna 840. The wireless communicationinterface 863 can typically include the RF circuit 864, and the like.The RF circuit 864 may include a mixer, a filter, an amplifier, and thelike, and transmits and receives the wireless signal via the antenna840. The wireless communication interface 863 may include a plurality ofthe RF circuits 864 as illustrated in FIG. 15, and the plurality of RFcircuits 864 may respectively correspond to, for example, the pluralityof antenna elements. Note that, although FIG. 15 illustrates an examplein which the wireless communication interface 863 includes the pluralityof RF circuits 864, the wireless communication interface 863 may includea single RF circuit 864.

The eNB 800, eNB 830, base station device 820, or base station device850 illustrated in FIGS. 14 and 15 can correspond to the base stationdevice 1 described with reference to FIG. 8 and the like.

[Application Example of Terminal Device]

First Application Example

FIG. 16 is a block diagram illustrating an example of a schematicconfiguration of a smartphone 900 as the terminal device 2 to which thetechnology according to the present disclosure can be applied. Thesmartphone 900 includes a processor 901, a memory 902, a storage 903, anexternal connection interface 904, a camera 906, a sensor 907, amicrophone 908, an input device 909, a display device 910, a speaker911, a wireless communication interface 912, one or more antennaswitches 915, one or more antennas 916, a bus 917, a battery 918, and anauxiliary controller 919.

The processor 901 may be, for example, a CPU or a System on Chip (SoC),and controls functions of an application layer and other layers of thesmartphone 900. The memory 902 includes a RAM and a ROM, and stores aprogram executed by the processor 901, and data. The storage 903 caninclude a storage medium such as a semiconductor memory or a hard disk.The external connection interface 904 is an interface for connecting anexternal device such as a memory card or a universal serial bus (USB)device to the smartphone 900.

The camera 906 includes, for example, an imaging element such as acharge coupled device (CCD) or a complementary metal oxide semiconductor(CMOS), and generates a captured image. The sensor 907 can include, forexample, a sensor group such as a positioning sensor, a gyro sensor, ageomagnetic sensor, and an acceleration sensor. The microphone 908converts sound input to the smartphone 900 into a sound signal. Theinput device 909 includes, for example, a touch sensor that detects atouch on a screen of the display device 910, a keypad, a keyboard, abutton, a switch, or the like, and accepts operation or informationinput from a user. The display device 910 includes a screen such as aliquid crystal display (LCD) or an organic light emitting diode (OLED)display, and displays an output image of the smartphone 900. The speaker911 converts the sound signal output from the smartphone 900 into sound.

The wireless communication interface 912 supports any cellularcommunication system such as LTE or LTE-Advanced, and executes wirelesscommunication. The wireless communication interface 912 can typicallyinclude a BB processor 913, an RF circuit 914, and the like. The BBprocessor 913 may perform, for example, encoding/decoding,modulation/demodulation, multiplexing/demultiplexing, and the like, andexecutes various types of signal processing for wireless communication.On the other hand, the RF circuit 914 may include a mixer, a filter, anamplifier, and the like, and transmits and receives a wireless signalthrough the antenna 916. The wireless communication interface 912 may bea one-chip module in which the BB processor 913 and the RF circuit 914are integrated together. The wireless communication interface 912 mayinclude a plurality of the BB processors 913 and a plurality of the RFcircuits 914 as illustrated in FIG. 16. Note that, although FIG. 16illustrates an example in which the wireless communication interface 912includes the plurality of BB processors 913 and the plurality of RFcircuits 914, the wireless communication interface 912 may include asingle BB processor 913 or a single RF circuit 914.

Moreover, in addition to the cellular communication system, the wirelesscommunication interface 912 may support another type of wirelesscommunication system, such as a near field communication system, aproximity wireless communication system, or a wireless local areanetwork (LAN) system, and in that case, the wireless communicationinterface 912 may include the BB processor 913 and the RF circuit 914for each wireless communication system.

Each of the antenna switches 915 switches connection destinations of theantenna 916 among a plurality of circuits (for example, circuits fordifferent wireless communication systems) included in the wirelesscommunication interface 912.

Each of the antennas 916 includes a single or a plurality of antennaelements (for example, a plurality of antenna elements constituting aMIMO antenna), and is used for transmission/reception of a wirelesssignal by the wireless communication interface 912. The smartphone 900may include a plurality of the antennas 916 as illustrated in FIG. 16.Note that, although FIG. 16 illustrates an example in which thesmartphone 900 includes the plurality of antennas 916, the smartphone900 may include a single antenna 916.

Moreover, the smartphone 900 may include the antenna 916 for eachwireless communication system. In that case, the antenna switch 915 maybe omitted from the configuration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903,the external connection interface 904, the camera 906, the sensor 907,the microphone 908, the input device 909, the display device 910, thespeaker 911, the wireless communication interface 912, and the auxiliarycontroller 919 to each other. The battery 918 supplies power to eachblock of the smartphone 900 illustrated in FIG. 16 via a feed linepartially illustrated by a broken line in the figure. The auxiliarycontroller 919 operates the minimum necessary functions of thesmartphone 900 in the sleep mode, for example.

Second Application Example

FIG. 17 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device 920 to which the technologyaccording to the present disclosure can be applied. The car navigationdevice 920 includes a processor 921, a memory 922, a global positioningsystem (GPS) module 924, a sensor 925, a data interface 926, a contentplayer 927, a storage medium interface 928, an input device 929, adisplay device 930, a speaker 931, a wireless communication interface933, one or more antenna switches 936, one or more antennas 937, and abattery 938.

The processor 921 may be, for example, a CPU or an SoC, and controls anavigation function and other functions of the car navigation device920. The memory 922 includes a RAM and a ROM, and stores a programexecuted by the processor 921, and data.

The GPS module 924 uses GPS signals received from GPS satellites tomeasure a location (for example, latitude, longitude, and altitude) ofthe car navigation device 920. The sensor 925 can include, for example,a sensor group such as a gyro sensor, a geomagnetic sensor, and anatmospheric pressure sensor. The data interface 926 is connected to anin-vehicle network 941 via a terminal (not illustrated), for example,and acquires data generated on the vehicle side such as vehicle speeddata.

The content player 927 reproduces a content stored in a storage medium(for example, CD or DVD) inserted in the storage medium interface 928.The input device 929 includes, for example, a touch sensor that detectsa touch on a screen of the display device 930, a button, a switch, orthe like, and accepts operation or information input from a user. Thedisplay device 930 includes a screen such as an LCD or an OLED display,and displays a navigation function or an image of a content to bereproduced. The speaker 931 outputs sound of the navigation function orthe content to be reproduced.

The wireless communication interface 933 supports any cellularcommunication system such as LTE or LTE-Advanced, and executes wirelesscommunication. The wireless communication interface 933 can typicallyinclude a BB processor 934, an RF circuit 935, and the like. The BBprocessor 934 may perform, for example, encoding/decoding,modulation/demodulation, multiplexing/demultiplexing, and the like, andexecutes various types of signal processing for wireless communication.On the other hand, the RF circuit 935 may include a mixer, a filter, anamplifier, and the like, and transmits and receives a wireless signalthrough the antenna 937. The wireless communication interface 933 may bea one-chip module in which the BB processor 934 and the RF circuit 935are integrated together. The wireless communication interface 933 mayinclude a plurality of the BB processors 934 and a plurality of the RFcircuits 935 as illustrated in FIG. 17. Note that, although FIG. 17illustrates an example in which the wireless communication interface 933includes the plurality of BB processors 934 and the plurality of RFcircuits 935, the wireless communication interface 933 may include asingle BB processor 934 or a single RF circuit 935.

Moreover, in addition to the cellular communication system, the wirelesscommunication interface 933 may support another type of wirelesscommunication system, such as a near field communication system, aproximity wireless communication system, or a wireless LAN system, andin that case, the wireless communication interface 933 may include theBB processor 934 and the RF circuit 935 for each wireless communicationsystem.

Each of the antenna switches 936 switches connection destinations of theantenna 937 among a plurality of circuits (for example, circuits fordifferent wireless communication systems) included in the wirelesscommunication interface 933.

Each of the antennas 937 includes a single or a plurality of antennaelements (for example, a plurality of antenna elements constituting aMIMO antenna), and is used for transmission/reception of a wirelesssignal by the wireless communication interface 933. The car navigationdevice 920 may include a plurality of the antennas 937 as illustrated inFIG. 17. Note that, although FIG. 17 illustrates an example in which thecar navigation device 920 includes the plurality of antennas 937, thecar navigation device 920 may include a single antenna 937.

Moreover, the car navigation device 920 may include the antenna 937 foreach wireless communication system. In that case, the antenna switch 936may be omitted from the configuration of the car navigation device 920.

The battery 938 supplies power to each block of the car navigationdevice 920 illustrated in FIG. 17 via a feed line partially illustratedby a broken line in the figure. Furthermore, the battery 938 accumulatespower supplied from the vehicle side.

Furthermore, the technology according to the present disclosure may beimplemented as an in-vehicle system (or vehicle) 940 including: one ormore blocks of the car navigation device 920; the in-vehicle network941; and a vehicle-side module 942. The vehicle-side module 942generates vehicle side data such as vehicle speed, engine speed, orfailure information, and outputs the generated data to the in-vehiclenetwork 941.

Note that, the effects described in the present description are merelyillustrative or exemplary and not restrictive. That is, the technologyaccording to the present disclosure can exhibit other effects obvious tothose skilled in the art from the description of the present descriptiontogether with the above-described effects or in place of theabove-described effects.

Note that, the following configurations also belong to the technicalscope of the present disclosure.

(1)

A terminal device that communicates with a base station device, theterminal device including:

a reception unit that receives a data channel including one or morepieces of data; and

a transmission unit that transmits response information to the data onthe basis of a parameter regarding reliability of the data.

(2)

The terminal device according to (1), in which the response informationis repeatedly transmitted on a predetermined number of different controlchannels.

(3)

The terminal device according to (2), in which the predetermined numberis determined on the basis of the parameter regarding the reliability.

(4)

The terminal device according to (2) or (3), in which repeatedtransmission of the response information is stopped in a case whereretransmission of the data is received.

(5)

The terminal device according to any one of (2) to (4), in which aplurality of pieces of the response information for different pieces ofthe data are multiplexed and transmitted in each of the controlchannels.

(6)

The terminal device according to (5), in which the number of theplurality of pieces of response information is determined on the basisof the maximum multiplexing number set from at least the base stationdevice.

(7)

The terminal device according to (5), in which the control channels aredetermined on the basis of the number of the plurality of pieces ofresponse information.

(8)

The terminal device according to any one of (1) to (7), in which theparameter regarding the reliability is given by at least a receptiontiming of the data.

(9)

The terminal device according to any one of (1) to (7), in which theparameter regarding the reliability is given by at least a transmissiontiming of the response information to reception of the data.

(10)

The terminal device according to any one of (1) to (7), in which theparameter regarding the reliability is given by at least the number oftimes of repeated transmission of the response information.

(11)

The terminal device according to any one of (1) to (7), in which theparameter regarding the reliability is given by at least controlinformation for the data channel.

(12)

The terminal device according to any one of (1) to (11), in which theparameter regarding the reliability controls an encoding rate of theresponse information.

(13)

The terminal device according to any one of (1) to (11), in which theparameter regarding the reliability controls a size of a resource usedfor transmission of the response information.

(14)

A base station device that communicates with a terminal device, the basestation device including:

a transmission unit that transmits a data channel including one or morepieces of data; and

a reception unit that receives response information to the data on thebasis of a parameter regarding reliability of the data.

(15)

A communication method used by a terminal device that communicates witha base station device, the communication method including:

receiving a data channel including one or more pieces of data; and

transmitting response information to the data on the basis of aparameter regarding reliability of the data.

(16)

A communication method used by a base station device that communicateswith a terminal device, the communication method including:

transmitting a data channel including one or more pieces of data; and

receiving response information to the data on the basis of a parameterregarding reliability of the data.

(17)

A recording medium that records a program for causing a computer tofunction as:

a reception unit that receives a data channel including one or morepieces of data; and

a transmission unit that transmits response information to the data onthe basis of a parameter regarding reliability of the data.

(18)

A recording medium that records a program for causing a computer tofunction as:

a transmission unit that transmits a data channel including one or morepieces of data; and

a reception unit that receives response information to the data on thebasis of a parameter regarding reliability of the data.

REFERENCE SIGNS LIST

-   1 Base station device-   101 Upper layer processing unit-   103 Control unit-   105 Reception unit-   107 Transmission unit-   2 Terminal device-   201 Upper layer processing unit-   203 Control unit-   205 Reception unit-   207 Transmission unit

1. A terminal device that communicates with a base station device, theterminal device comprising: a reception unit that receives a datachannel including one or more pieces of data; and a transmission unitthat transmits response information to the data on a basis of aparameter regarding reliability of the data.
 2. The terminal deviceaccording to claim 1, wherein the response information is repeatedlytransmitted on a predetermined number of different control channels. 3.The terminal device according to claim 2, wherein the predeterminednumber is determined on a basis of the parameter regarding thereliability.
 4. The terminal device according to claim 2, whereinrepeated transmission of the response information is stopped in a casewhere retransmission of the data is received.
 5. The terminal deviceaccording to claim 2, wherein a plurality of pieces of the responseinformation for different pieces of the data are multiplexed andtransmitted in each of the control channels.
 6. The terminal deviceaccording to claim 5, wherein a number of the plurality of pieces ofresponse information is determined on a basis of a maximum multiplexingnumber set from at least the base station device.
 7. The terminal deviceaccording to claim 5, wherein the control channels are determined on abasis of a number of the plurality of pieces of response information. 8.The terminal device according to claim 1, wherein the parameterregarding the reliability is given by at least a reception timing of thedata.
 9. The terminal device according to claim 1, wherein the parameterregarding the reliability is given by at least a transmission timing ofthe response information to reception of the data.
 10. The terminaldevice according to claim 1, wherein the parameter regarding thereliability is given by at least a number of times of repeatedtransmission of the response information.
 11. The terminal deviceaccording to claim 1, wherein the parameter regarding the reliability isgiven by at least control information for the data channel.
 12. Theterminal device according to claim 1, wherein the parameter regardingthe reliability controls an encoding rate of the response information.13. The terminal device according to claim 1, wherein the parameterregarding the reliability controls a size of a resource used fortransmission of the response information.
 14. A base station device thatcommunicates with a terminal device, the base station device comprising:a transmission unit that transmits a data channel including one or morepieces of data; and a reception unit that receives response informationto the data on a basis of a parameter regarding reliability of the data.15. A communication method used by a terminal device that communicateswith a base station device, the communication method comprising:receiving a data channel including one or more pieces of data; andtransmitting response information to the data on a basis of a parameterregarding reliability of the data.
 16. A communication method used by abase station device that communicates with a terminal device, thecommunication method comprising: transmitting a data channel includingone or more pieces of data; and receiving response information to thedata on a basis of a parameter regarding reliability of the data.
 17. Arecording medium that records a program for causing a computer tofunction as: a reception unit that receives a data channel including oneor more pieces of data; and a transmission unit that transmits responseinformation to the data on a basis of a parameter regarding reliabilityof the data.
 18. A recording medium that records a program for causing acomputer to function as: a transmission unit that transmits a datachannel including one or more pieces of data; and a reception unit thatreceives response information to the data on a basis of a parameterregarding reliability of the data.